Kāyastha or Kayasth (Hindi: कायस्थ) is a caste of India. They are the only sect who are referred to as direct “blood” progeny of a Vedic God in the religious texts and the only ancestor worshipping  ShriChitragupt Puja sect of Hinduism also called Chitranshi/Devputra. They are said in the Vedas and Puranas to have a dual-caste status i.e. Brahmin and Kshatriya. They are mainly spread across North India and are a sub-sect of Brahmins whose ancient profession was writing. 
The Sanskrit dictionary at Hindunet.org defines Kayastha as follows:
ka_yastha, ka_yata a man belonging to the writer-caste; a tribe of bra_hman.as whose employment is writing (Ka.)(Ka.lex.)
BRAHMINS by vedah.net  is an arcticle on who the brahmins are and the various sub-groups of Brahmins. The Kayastha Brahmins are mentioned at sl.no. 15 (in alphabetic order).
The Brahmins : A List of Brahmin Communities is an extensive list prepared by Kamat.com  of all Brahmin communities in India. Kayastha Brahmins are mentioned (in alphabetic order).
Vyoma Samhita quoted in Shabda−Kalpadrum says:
The Kayasthas have sprung from the kaya or body of Lord Brahma. They are similar in rank to Brahmans.
The major differences between this ministerial class and the proper priestly class, started around 1500 years ago in the Kingdom of Kashmir, where each accused the other of misusing their power.  Colonial translation of Kalhana's Rajatarangini: A Chronicle of the Kings of Kashmir: By M.A. Stein. WARNING: HIGHLY NEGATIVE TREATMENT OF THE CHARACTER OF KAYASTHAS.  The great divide: between the Kayasthas and the Kashmiri Pandits.
Kayastha have been described in the oldest of the Puranas, Smritis and Shrutis:
According to the Vedic scriptures, the souls of men after death receive rewards and punishments according to their sins and virtues, and hence it is believed that good and bad deeds of men are not destroyed. The souls of men after death go to Yamapuri which is presided over by the deities called Yamas who keep records of men’s actions and accordingly give them their dues. The principal Yama is called Yamaraja or Dharamaraja, that is, the ruler of Yamapuri or the King of Laws.
The Yama Samhita which is an extract from the 9th Chapter of Ahilya Kamdhenu, a work of Hindu Law, says that Dharamaraja complained to Lord Brahma about his difficulties in performing his most responsible duties of keeping records of the deeds of men and doing justice to them. Lord Brahma went into meditation. Shree Chitragupta sprang from his body and stood before him bearing an inkpot and a pen. The God Brahma (Creator) said: "Because you are sprung from my body (kaya), therefore you shall be called Kayastha and as you existed in my body unseen I give you the name of Chitragupta." He then assumed charge of Yamapuri. Dharma Sharma married his daughter Irawati to Chitragupta and Manuji, son of Surya (the Sun) married his daughter Sudakhina to him." Chitragupta had eight sons from the former and. four from the latter and these twelve sons became the progenitors of the twelve sub−divisions of the Chitraguptavansi Kayasthas, namely, Mathur, Gaur, Nigam, Ashthana, Kulshretha, Suryadwaja, Balmika Bhatnagar, Srivastava,Ambastha, Saxena and Karana.
In Padma Purana, Uttar Khanda, it says that Shree Chitragupta had twelve sons by two wives. They were all invested with the sacred thread and were married to Nagakanyas. They were the ancestors of the twelve sub−divisions of the Kayasthas.
The same legend with some slight difference is given inmost of the Puranas.
Padma Purana after stating the legend says: "Shree Chitragupta was placed near Dharamaraj to register the good and evil actions of all sentient beings,that he was possessed of supernatural wisdom and became the partaker of sacrifices offered to the gods and fire. It is for this reason that the twice−born always give him oblations from their food. As he sprang from the body of Lord Brahma he was called Kayastha of numerous gotras on the face of the earth."
In Shristhi Khanda the same Purana says that the sacrificial rites and study of the Kayasthas should be of the Vedas and supporting scriptures and their occupation related to writing.
Bhavishya Purana states that God, the Creator, gave the name and duties of Chitragupta as follows:
Because you have sprung from my body, therefore, you shall be called Kayastha and shall be famous in the world by the name of Chitragupta. Oh my son, let your residence be always in the region of the god of justice for the purpose of determining the merits and demerits of men.
Vignana Tantra says the same thing.
The same is the enjoinment of Lord Brahma to Shree Chitragupta according to Brihat Brahma Khanda. He was named Kayastha having sprung from the body (kaya) of Lord Brahma. He was directed to perform all sanskars and to have writing as his profession.
Garuda Purana describes the imperial throne of Shree Chitragupta in Yamapuri holding his Court and dispensing justice according to the deeds of men and maintaining their record, in the following words:
(There Dharmaraja, Chitragupta, Sravana and others see all sins and virtues which remain concealed in the bodies of men).
Similarly, Apastamba Shakha of the Veda quoted in Shabda−Kalpadrum 2nd part, page 228, Shabda 20,
under Kshatriya, states that Kayasthas are Kshatriyas. Chitragupta who reigns in heaven and his son Chaitrarath, who was light of the family, meritorious and of illustrious deads ruled on earth for a long time as King of Chitrakoot near Allahabad. Meru Tantra quoted in Shabda−Kalpadrum under the word ’Kshatriya’ supports the same view.
The Mahabharata (Anusasan Parva, Chap. 130) recites the teaching of Shree Chitragupta requiring men to do virtuous and charitable acts and performing Yagya, saying that men are rewarded or punished according to their good or bad deeds.
Turning to the Smritis, Vishnu in Chap. VII, verse 3, says that a document attested by the King is one which is written or prepared by a Kayastha and stamped with the finger prints of the head of the department.
The words are Virihat Parasara in Chap. X, Sloka 10 says. Kayasthas should be appointed as writers, they being expert in writing.
Again in Chap. I, Sloka 235, he says that Danda−dhrita the Magistrates and Judges of the Courts should be (dharmagya), persons versed in laws and good administration, Kayasthas, who are versed in the art of writing.
Vyas says that the writer and the accountant should be that is versed in Mimansa (Srutis) and Vedas (Adhyayana) as explained by Mitakshara in commenting upon Yajnavalkya, Chap. II, Sloka 2, which says that the King’s Councillors should be versed in the sacred books of Mimansa and Vedas, expert in law, truthful and impartial.
Similarly, Shukraaiti in Chap. XXXII, Sloka 420, describes Kayasthas as lekhaks, and in Chap. II, versa 178, says that the accountant and lekhak knew the Vedas, Smritis and Puranas.
Yajnavalkya in Slokas 317 to 320 describes how the edicts of the king should be written, sealed and promulgated. Apararka in his commentary upon these Slokas quotes from Vyas and shows that these edicts should be written by lekhaks, the ministers of war and peace (sandhi vigraha kari), and that they should be promulgated to the gentry and officials among whom Kayasthas have been mentioned.
Similarly, Vijnanesvara in his Mitakshara commenting upon these Slokas says:
He (King) should cause it to be recorded by that officer of his, who is in charge of war and peace (i.e. by a Kayastha), and not by anybody else.
As says a Shruti: That officer of his, who is sandhi vigraha kari or the officer in charge of peace and war should be its writer (lekhak).
Yajnavalkya uses the word "Kayastha" in Slokas 335 36, Chap. I. Commenting upon this, Mitakshara says that Kayasthas are accountants and writers. He makes the word "Kayasthas synonymous with accountants and writers. Similarly, Apararka says that Kayasthas were revenue−collectors (kar−adhi−krita).
The accountants and scribes constitute one of the ten parts of a judicial proceeding.
Brihaspati says the same thing, as quoted in Prasara Madhava, Vyavahara Kanda.
According to the Smritis, the officers of the realm, such as, ministers of peace and war, courtesans and Councillors, Governors and headmen of villages should be men versed in the Sastras, valorous and born of noble family, pure, intelligent, affluent in wealth and of tested virtue and comprehension: Manu, Chap. VII, Verses 54 to 121 Yajnavalkya, Chap. I, Verse 312.
Kayasthas in recent times are the giver of the Hare Krishna Movement-ISKCON(Swami Prabhupada), Transcendental Meditation(Maharshi Mahesh Yogi), Integral yoga(Sri Aurobindo), Kriya Yoga(Paramahansa Yogananda of ‘Autobiography of a Yogi’ fame) and Vedanta(Swami Vivekananda) to the western world.
Types of Kayasths
There are of three kinds of Kayasthas (by blood) and four types in total:
1. Chitragupta Kayasthas (Brahma Kayashta or Kayastha Brahman). Caste-Status:Brahmin; usually 'Kayastha' in most ancient Vedic literature refers to this sect, henceforth Kayastha in this article would refer to the Chitragupt Kayastha unless otherwise stated.
BRAHMINS by vedah.net is an arcticle on who the brahmins are and the various sub-groups of Brahmins. The Kayastha Brahmins are mentioned at sl.no. 15 (due to alphabetic order).
The Brahmins : A List of Brahmin Communities is an extensive list prepared by Kamat.com of all Brahmin communities in India. Kayastha Brahmins are mentioned in the alphabetic order.
The Sanskrit dictionary at Hindunet.org defines ‘Kayastha’ as follows:
ka_yastha, ka_yata —a man belonging to the writer-caste; a tribe of bra_hman.as whose employment is writing (Ka.)(Ka.lex.)
2. Chandraseniya Kayastha Prabhu (Rajanya Kshatriya Kayasthas- from the Haiyaya family) Caste-Status:Kshatriya,
3. Kayasthas of the mixed blood. Caste-Status:Kshatriya or others as per the law of Hindu Shastras and
4. Kayasthas by name or virtue of profession (not by blood). Caste-Status:depends on history of that group and may vary with regions
The Kayastha trace their genealogy from Lord Chitragupta. It is said that after Lord Brahma had created the four Varnas (Brahmins, Kshatriyas, Vaishyas, and Shudras), Yama (Dharamraj) requested Lord Brahma to help him record the deeds, both good and evil, of men and to administer justice.
According to the scriptures, Lord Brahma went into meditation for 11,000 years and when he opened his eyes he saw a man holding a pen and ink-pot in his hands, as well as a sword girdled to his waist. Lord Brahma spoke: ``Thou hast been created from my body (Kaya); therefore, shall thy progeny be known as the Kayasthas. Thou hast been conceived in my mind (Chitra) and in secrecy (gupta); thy name shall also be Chitragupta. Brahma then enjoined him to dispense justice and punish those who violated the dharma. Thus, the Kayasthas were accorded a dual caste, Brahman/Kshatriya.
In the legends of Chitragupta as well as in the Vedas, he is referred to as the greatest king, while the rest are "Rajakas," or little kings.
चित्र इद राजा राजका इदन्यके यके सरस्वतीमनु ।
पर्जन्य इव ततनद धि वर्ष्ट्या सहस्रमयुता ददत ॥ RIG VEDA Book 8/ Hymn 21/ Stanza 18
In the Garud Purana, Chitragupta is hailed as the first man to give the script.
"Chitragupta namastubhyam vedaksaradatre" (Obeisance to Chitragupta, the giver of letters)
The Rig Veda mentions an invocation to be made to Chitragupta before offering sacrifice. There is also a special invocation to Chitragupta as Dharmraj (Lord of Justice) to be made at the performance of shradh or other rituals.
"Om tat purushaya vidmahe Chitragupta dhimahi tena lekha prachodayata."
The priests also pay reverence to Shri Chitragupta :
"Yamam Dharmarajya Chitraguptaya vain namah."'
Lord Chitragupta is the Athi Devathai for Kethu, one of the Navagrahas, and those who worship Chitragupta, would be bestowed with prosperity. Also the evil effects of Kethu during its transit period would be mitigated.
The birthday of Shree Chitraguptaji is celebrated on Yamadwitiya and Chitraguptajayanti Puja is performed on this day.
The privileges of performing religious duties related to Yamaraj and Chitraguptaji are reserved by the Kayasthas. Of these, one of most important is the Chitraguptajayanti Puja. The greatness of this yajna is that whoever performs it, is spared the punishments of hell, whatever his records of deeds be.
The ancient story related to this is now told. There was a mighty king, who had subjugated the whole world by his ambition to be the supreme King of Kings. The stories of his cruel deeds had spread to all the corners of the world. His name was uttered only with great respect and a greater fear at heart, for everyone knew that his deeds were vile and extreme. His name was Sudass, the King of Saurastra, his capital, from where he ruled his vast empire with an iron fist. He was known to be one of most ‘Adharmi’ (nearest meaning: ‘irreligious and one who crosses the threshold of Dharma’) and perpetrator of ‘Paap’ (nearest meaning: ‘sins’). All through his extensive kingdom, it was known that their king had never ever done a ‘Punya’ in his evil life. This King was fond of hunting, and once on a hunting spree, was lost in the jungle. Unable to find his way out, and unknown to fears of any kind, he decided to see what his jungles were like. He went on exploring the jungles when he heard the sound certain ‘Mantras’ coming from North. He headed for the place where the mantras where being chanted. There he found a few Brahmins performing a yajna and few common people sitting to witness this. The king lost his cool on seeing a puja being performed without his consent. He thus spoke with thunder in his voice:
“I am King Sudass, the King of Kings. Salute me you foolish men. Who are you and what are you doing here? I demand an answer.”
The group of priests kept on chanting their mantra and paid no heed to the angry king, all the while people sitting at some distance and witnessing the yajna being performed kept mum, being afraid of the king. On being so ignored the king lost his cool and raised his sword to hit the head priest. Seeing this, the youngest of the priests stood up and spoke thus:
“Stop! King Sudass, stop! Don’t turn this opportunity into a disaster. You have been sent here not to be condemned but saved.”
On hearing these words the King became interested and said, “You, young boy, have great courage and knowledge for your age. Will you elaborate on what you have just said?”
The young priest said to the King, “O Sudass, you call yourself the King of Kings: how mistaken you are! When you die you would be subjugated to such punishments that your pride will vanish in thin air. You want to know who these men are and what are they doing and what is the purport of my speech. Then listen:
We are the sons of Lord Chitragupta, whom the great Rigveda call the true King of Kings, and whose title you are not worth stealing. We are Kayasthas and we are performing yajna to our Lord Yamaraj and our progenitor Maharaj Chitrgupta on this great day of Yamadwitiya. O King Sudass, whoever performs this puja is spared the punishments of hell. You can be free from hell if you will only submit to Yamaraj and Chitraguptaji, who has the record of all the sins that you have done in your vile life! Nothing in this world is hidden from Him and only He could save you. On one hand is salvation and on the other is hell. Come, join us or kill us all.”
The king was left dumbfounded and followed the young priest as if in a trance. He then performed the puja with full devotion and the exact procedure. Thereafter he took the ‘prasaad’ and went back to his kingdom with the other men.
With the passage of time there came the day when the Yamadoots came to take him away with them, to the Yamaloka. The Yamadoots tied the king's soul in chains and pulled it to the court of Yamaraja. When the bleeding and dilapidated King reached the court of Yamaraj, Lord Chitragupta opened the book of his deeds and thus spoke to Yamaraj. “O great Yamaraj, I can only see a life full of sins in his case, yet this king did perform our yajna in his life time? He performed the puja on Karthik shukla dwitiya and with full devotion and the right procedure. He performed our and your ‘vrat’ on that day. Thereby, all his ‘paaps’ have been nullified and according to the rules of Dharma, he cannot be sent to hell.” Thus the king was saved from hell and till this day whoever performs the Chitraguptajayannti puja is spared the punishments of hell.
There are several temples in India, particularly in South India, enshrining the Lord Chitragupta. The most famous of them is located at Kanchipuram , Tamilnadu state, India.
One of the ancient temples of Chitraguptaji is situated in Khajuraho. Pictures of this temple can be found at http://chitraguptvanshi.wetpaint.com .
 The Family Tree
Shree Chitraguptaji married Devi Nandani and Devi Shobhavati and had twelve divine Sons. The 12 Sons started the 12 main branches of Brahma Kayastha.
The 12 clans of Brahma Kayastha:
Srivastava or Shrivastava
 Sons of Devi Shobhavati
Charu (Mathur): He was a disciple of sage Mathure, Rashi name was Dhurandhar, was married to Devi Pankajakshi and worshipped Devi Durga. Mathureshwari. Maharaj Chitraguptji sent Shree Charu to establish a Kingdom in the Mathara region (between Mahanadi and Krishna River in Orissa). His descendants were known as the Mathurs. After defeating the demons, a term regularly used for the anti-Vedic tribes, they established the Kingdom of Mathara. This done, they also propagated to other part of Aryavartha. In the meanwhile they were further divided into 3 sub-divisions 1.The Mathurs of Mathara, 2.The Pancholi or Panchali of Pnachal Kingdom where in garwhal hills there is town of Mathara 3.The Kacchi of Gujrat. The Mathurs seemed to enjoy a long history of ruling many Kingdoms, the most important of which was Ayodhya, ruled by them before the Raghuvanshis took the reign. They are divided into 84 Als. They established Pandya Kingdom covering Madurai Trinivelli etc. They sent an emissary to the Roman Emperor Augustus Ceasar.
Sucharu (Gaur) गौड़ : He was a disciple of sage Vasishtha, Rashi name was Dharamdutta and worshipped Devi Shakambari. Maharaj Chitraguptji sent Shree Sucharu to establish a Kingdom in the Gaud region. Shree Sucharu married Devi Mandhiya, the daughter of Nagaraj Vasuki. The gaurs are divided into five divisions: 1.Khare, 2.Doosre, 3.Bengali, 4.Dehlavi, 5.Vadanyuni. Gaur Kaystha have been further sub divided in 32 Als. Bhagdutta of Mahabharat and Rudradutta of Kalinga were famous.
Chitraksh (Bhatnagar): He was a disciple of sage Bhat, was married to Devi Bhadrakalini and worshipped Devi Jayanti. Maharaj Chitraguptji sent Shree Chitraksh to establish a Kingdom in the region of Bhat river at Bhattdesh and Malwa.They established Chittor and Chitrakoot He settled then there and his progeny came to be known as Bhatnagar. They are divided into 84 Als.
Matimaan (Saxena): He was married to Devi Kokalesh and worshipped Devi Shakambari. Maharaj Chitraguptji sent Shree Matimaan to establish a Kingdom in the Shak region. His(Shree Matimaan’s) son was a great warrior and established His kingdom in the modern day Kabul-Kandhar and Eurasia region and as they were sakha ( friends Of Sena )the progeny was called Shaksena or Saksena, a part of modern Iran was under their rule. Today they are abundantly found in the regions of Kannuaj,Pilibhit, Bareilly, Shahjahanpur, Badayu, Farrukhabad, Etta, Mainpuri, Aligarh. They are divided into Khare and Dusare and had 106 main Als at present. According to RC Majumdar, they were kings Shena of Shakas hence Shakashena which anglicised to Saxena.
Himvaan (Ambashth): His Rashi name was Sarandhar, was married to Devi Bhujangakshi and worshipped Devi Amba-Mata. Settled in Girnar and kathiawar area called Amba-sthan, hence the name. Shree Himvaan had five divine sons Shree Nagasen, Shree Gayasen, Shree Gayadatta, Shree Ratanmool and Shree Devdhar and they married Gandharvyakanyas. These five Sons settled at different locations and accordingly their lineage spread their rule over these and were further divided into: Nagasen: 24 Als, Gayasen: 35 Als , Gayadatta: 85 Als, Ratanmool: 25 Als, Devdhar: 21 Als. Later they settled in Punjab after their defeat by Alexander's general and then by Chandragupt Maurya.
Chitracharu (Nigam): His Rashi name was Sumant, was married to Devi Ashgandhmati and worshipped Devi Durga. Maharaj Chitraguptji sent Shree Chitracharu to establish a Kingdom in the Mahakoshal and the Nigam region (on the bank of river Saryu). His progeny were very proficient in the rules laid in Vedas and the Shastras, hence Nigam. Today they live in Kanpur, Fatehpur, Hamirpur, Banda, Jalon, Mahoba. They are divided into 43 main Als.
Aruncharu (Karna): His Rashi name was Damodar, was married to Devi Kamakala and worshipped Devi Laxmi. They were Vaishnavites. Maharaj Chitraguptji sent Shree Aruncharu to establish a Kingdom in the Karna region (modern day Karnataka). His progeny slowly migrated to the Northern Kingdoms and now live abundantly in the present day Nepal, Orissa and Bihar. The Bihar branch is further divided into two; namely the ‘Gayaval Karna’ who settled in Gaya and the ‘Maithil-Karna’ who settled in the Mithila region.Later they adopted Buddhism. They are divided into an astounding 360 Als; this huge figure is attributed to the families who migrated in different phases from South. The clan has nothing to do with Karna of Mahabharata.
Jitendra (Kulshreshtha): His Rashi name is Sadananda, was married to Devi Manjubhashini and worsipped Devi Laxmi. Maharaj Chitraguptji sent Shree Atiyendriya(also known as Jitendra) to establish a Kingdom in the Kannauj region. Shree Atiyendriya was one of the most religious and pious ascetic of the twelve Sons. He was known as ‘Dharmatama’ and ‘Pundit’ and was a master of passions; His progeny came to be known as Kulshrestha. Today the Kulshreshthas live abundantly in Mathura, Agra, Fawrookhabad, Etah, Etahwa and Mainpuri.A few are in Nandigaon ,Benga. Like Shree Shekhar kulsreshtha and Sugam Kulshreshtha as in Jalesar ( Etah ) Both of them were renowed writer.
 Sons of Devi Nandani
Shribhanu(Srivastava): His Rashi name was Dharamdwaj. Maharaj Chitraguptji sent Shree Shribhanu to establish a Kingdom in the Shrivaas(Srinagar)region in Kashmir and Kandhar. He was married to Nagaraj Vaasuki’s daughter Devi Padmini and two divine sons named Shree Devdatta and Shree Ghanshyam were born. Shree Devdatta got the rulership over Kashmir and Shree Ganshyam got the rulership over the banks of Sindhu river. They were called Srivastava ‘Khare’ born from second wife Kheri.Two divine sons named Shree Dhanvantari and Shree Sarvagya were born. They were called Srivastava ‘Doosre’.The Srivastavas are divided into 65 main Als.
Vibhanu (Suryadhwaj): His Rashi name was Shyamsunder, was married to Devi Malti. Maharaj Chitraguptji sent Shree Vibhanu to establish the Kingdom in northern parts of the Kashmir region. Since Mother Dakshina was the daughter of Suryadev, the progeny of Shree Vibhanu carried the emblem of the Sun God on their flags and were called Suryadhwaj.Jarasandha of Mahabharat and Jamnaya of Taxila were well known.Later they settled at Magadh
Vishwabhanu (Valmiki): His Rashi name was Deendayal and worshipped Devi Shakumbhari. Maharaj Chitraguptji sent Shree Vishwabhanu to establish a Kingdom in Valmiki region near Chirakoot and Narmada. Shree Vishwabhanu was married to Nagakanya Devi Bimbvati. He’s known to have spend a great part of his life practicing intense meditation(Tapasya) on the banks of river Narmada, when covered with the leaves of creeper Valmiki.His progeny were known as Valmiki.They became Vallabhpanthi. His son Shree Chandrakant settled in Gujarat while the other Sons migrated with their families to the North, near river Ganga and the Himalayas. Today they live in Gujarat and Maharashtra. They are also known as ‘Vallabhi Kayastha’ in Gujarat.
Viryabhanu (Asthana): His Rashi name Madhavrao, was married to Devi Singhdwani. Maharaj Chitraguptji sent Shree Viryabhanu to establish a Kingdom in Adhisthana. His progeny came to be known as Asthana as Ramnagar-Varanasi's king bestowed them with eight jewels.Some say that they had no fixed sthan, hence the name. Today the Asthanas live abundantly in various districts of U.P. In Bihar they live in Saran, Sivaan, Champaran, Mujjafarpur, Sitamadhi, Darbhanga, Bhagalpur regions. Their population is also notable in U.P.’s neighboring state M.P. They are divided into 5 main Als.
These twelve sub-castes are further divided into ALs. A Vansh originates from a King, a Rishi or a Deity and as it grows it divides itself in to several branches. The descendents start to build their own sub-Vansh depending upon the places and situations met, at the same time acknowledging their submission to the MOOL Vansh. These sub-Vansh add specific nouns to their names which in case of the Chirtagupta Vansha(Chitranshi) are called the Als (Kindly be clear upon the point that the 12 main sub-castes are acknowledged divisions based on the family of the 12 Sons, they are not called Als, their further divisions are what Als are) One has to be careful to avoid confusing them with Gotra. Gotra goes after the name of a Vedic Rishi, who was either a Guru, RajGuru or Progenitor of that Vansh. The gotra for a MOOL Vansh is always the same. It is Kashayap for the Kayasthas. Thus, a Vanshaz can be known from his Gotra and Al (The term Kul is often used for Al, though the former has a much broader meaning).The Als can be thousands in number and must be added to the name in conjunction with one of the 12 main sub-castes. The ignorance of this law is precisely the reason why so many can not find their surnames mentioned amongst the 12 main sub-castes.
 Aspects of Kayastha culture
Kayasthas practice family exogamy and caste endogamy preferring to marry within specific sub-castes. The individuals of same AL (see a definition of AL above) cannot intermarry, while those of same caste and different ALs can. To illustrate, individuals from the Srivastava sub-caste and the Pandey AL do not marry another Pandey of the Srivastava sub-caste, but may marry individuals belonging to another AL of the Srivastava sub-caste.
 Distinctive Worship
Kayasthas are unique from other Hindu castes in their worship of an ancestor, Shree Chitraguptaji and the practice of Kalam-Dawaat Pooja, a ritual in which pens, papers and books are worshiped. Both these rituals are performed on the Yama Dwitiya, this is the day when Shree Chitraguptji was created by Lord Bramha and Yamaraj got relieved of His duties and used this leave to visit His sister Devi Yamuna; hence the whole world celebrates Bhaiya dooj on this day and the Kayastha celebrate ShreeChitraguptajayanti, i.e. the 'Birthday' of their progenitor. Kayasthas have the singular distinction of being the only "Ancestor-worshipping" sect of Hinduism.
Of all the other castes in India, Kayasthas are the easiest to mingle with other castes. They did this when the Muslims came to India, and modern examples of this are Kayasthas outside India where they mingle with other castes more than they mingle among themselves. This cosmopolitan outlook distinguishes members of this caste, and along with the great emphasis on education, is to a large extent responsible for their success in changing times.
 Sense of humour
Kayastha are known for their sense of humour and wit. Whatever be the reason the Kayastha just can’t live without a good laugh. Many funny men and class clowns often turn out to be Kayasthas on closer examination. Others take their revenge, Kayastha are the subject of a series of jokes known as ‘Lalaji jokes’ in UP and Bihar. Unlike Punjab and NCR, the word "Lalaji" is exclusively used for the Kayasthas in UP and Bihar. The Lalaji is charecterized with a sharp wit, ever hungry desire to grab and total abstinence from violence. The jokes usually feature other characters like gupta, pande, gajodhar. Often the crow, for whatever reasons, is also involved in such jokes.
Example: Lalaji falls in a ditch. Gupta was passing by and saw lalaji, said "Lalaji hath dijiye"(Give me your hand). Lalaji stood still. Then came Pande, said "Areey gupta, hath dijiye nahi hath lijiye bolo"(Dont tell him to give his hand, ask him to take yours).
Another: A Kayastha caught a crow and was about to bite its neck. The crow asked him 'whats your caste' thinking all the while that the Kayastha would have to open his mouth to say "Kaa_yasth". The Kayastha said 'lala'.
 Ancient India
Kayastha ministers find mention in Hindu mythology. Prior to the Raghuvanshis, Ayodhya was ruled by Mathur Rulers, progeny of Chitragupta.
The Kayastha who are represented by the "Kayath" or the hereditary caste of the scribes of the present day, formed originally a sub-military class. The Anthropological Survey of India conducted a survey during the British Raj which concluded that the Kayastha community were also influential during the Mauryan period as administrators. Also, many proof have been found that the Hindu Kings used to grant lands to the Kayasthas, a practise enjoyed only by a particular caste. Also, it is but logical to consider the status of the Kayasthas when Sanskrit was the state language under the Hindu Kings.
The Kayastha were one of the most influential Caste in Kashmiri politics around 7th century  (ref. Rajatarangini).In these and contemporary Sanskrit literature we come across the Kayasthas being described as kings, financiers and advisers. King Lalitaditya Muktpida was one glorious King of a Kayastha dynasty of Kashmir.
The various scripts used by the Kayastha during most of the Ancient period can only be conjectured, but Brahmi certainly was extensively used and often praised as the scrit of the Vedas given by Bhagvaan Chitragupt himself.
 Islamic and Pre-independence India
The Kayastha caste's affinity for learning and socio-economic status, both enabled and dictated that the community develop expertise in the changing administrative policies and official languages, as different empires were established in India. The community learned and adapted terminology to Persian, Turkish, Arabic and later Urdu in Islamic India. Importantly, the community created, maintained and developed empire-wide administrative practices in monetary policy, jurisprudence and taxation.
The script used during this period was majorly Perso-Arabic script.
These roles continued into the colonial colonial era, where many Kayasthas were the first to learn English and become civil servants, tax officers, junior administrators, teachers, legal helpers and barristers. During this period, Kayastha community members were more likely (than other communities) to undertake academic training in England and often rose to the highest positions accessible to natives in British India. As a consequence of their relatively large proportion amongst Indian students abroad, and because many hit ceilings of progression because of racial status, community members played pivotal roles in the early political groups that questioned British rule in India.
The script used during this period was Kaithi. The name makes a very clear reference to the creators, the Kaystha are often referred as "Kayath" in middle ages. Kayasthas have a unique distinction of having a script - Kaithi - associated with their name. Kaithi (also known earlier as Kayati, Kayathi or Kayasthi), similar to Dev Nagri, was used mainly by Kayasthas in northern India. It has its own Unicode now and was the major contender in the race to become national script but was left behind due to being not known to masses.
 Modern India
Many Kayasthas were successful in adapting to post-independence India, becoming civil servants, bureaucrats and lawyers. The community's traditional association with higher education also led to heavy immigration to the west in the 1970's and 1980's as community members sought increased educational and research opportunities. Notable examples include the first President of India, Dr. Rajendra Prasad, the third Prime Minister, Lal Bahadur Shastri, social and religious reformer Swami Vivekananda, freedom fighter Subhash Chandra Bose and film-star Amitabh Bachchan.
 Prominent Kayasthas
Main article: List of Kayasthas
Dr Rajendra Prasad rose to become the first President of the Republic of India. Dr Sampurnanand was the first Chief Minister of U.P. and Governor of Rajasthan, besides being a literary figure. Jayaprakash Narayan brought down Indira Gandhi, Subhas Chandra Bose fought the British rule militarily. Shanti Swarup Bhatnagar, Satyendra Nath Bose and Jagdish Chandra Bose were eminent scientists. Munshi Prem Chand, Harivansh Rai Bachchan, Satyendra Chandra Mitra a freedom fighter, Raghupat Sahai "Firaque" Gorakhpuri, Dr Vrindavan Lal Verma, Dr. Ram Kumar Verma, Mahadevi Varma, Kamla Chaudhury, Dr Dharm Vir Bharti and Bhagavati Charan Verma have been men of letters. Swami Vivekanand and Maharishi Mahesh Yogi were philosophers. Alakh Kumar Sinha was the first Indian Inspector-General of Police., S.K. Sinha, PVSM, has served as Indian Ambassador to Nepal, Governor of Assam and Governor of Jammu & Kashmir. Amitabh Bachchan and Shatrughan Sinha have excelled in the film world, Raju Srivastava have done best in the field of Comedy, Mukesh, Sonu Nigam in the world of music, Ambarish Srivastava is in the field of Literature and Architecture . and Nirmala Srivastava who is Shri Mataji Nirmala Devi) is the founder of Sahaja Yoga, a new religious movement. Vikas Swarup, the author of Q&A (adapted as the Oscar winning film "Slumdog Millionaire") and Six Suspects, and a career Indian Diplomat, is from a prominent Kayastha family of Allahabad.
This is a list of noteworthy people of the Kayastha caste of India.
Maharishi Mahesh Yogi
Dr. Rajendra Prasad - The first President of India.
Netajee Subhash Chandra Bose
Loknayak Jayaprakash Narayan
Sri Lal Bahadur Shastri
C. D. Deshmukh
Renuka Devi Barkataki
Shiv Charan Mathur
Ram Ganesh Gadkari
Dr. Vrindavan Lal Verma
Harivansh Rai Bachchan
Bhagwati Charan Verma
Phanishwar Nath Renu
Acharya Shivpujan Sahay
Acharya Ramlochan Saran
Hari Krishna Nigam
Dr. K.C. GAUR
Science & technology
Dr. Shanti Swaroop Bhatnagar
Dr. Jagadis Chandra Bose
Dr.Satyendra Nath Bose
Dr.Prabhu Lal Bhatnagar
Sisir Kumar Mitra
Dr S P Srivastava
DR Ashwin Prakash
Arts and architecture
Ambarish Srivastava in architecture
Films, television and music
Neil Nitin Mukesh
Sir Jadunath Sarkar
Banarsi Prasad Saxena
Ashirwadi Lal Srivastava
Shib Sunder Das
Ganesh Shankar Vidyarthi
Bipin Chandra Pal
Subhash Chandra Bose
Rash Behari Bose
Saheed Jagatpati Kumar
Tushar Kanti Ghosh
Basanta Kumar De
Sir Sarat Kumar Ghosh
S. K. Sinha
Girish Chandra Saxena
Anami Narayan Roy