As I heard and visualised, the broad group called "Kayastha" originally belonged to Egypt. They had the profession of writers and record keepers in the courts of the Pharohs. At the advent of Christianity, and subsequently of Islam, they fled from Egypt and gradually landed in India. Being educated and versed in Arabic language, they found employment under various courts here,.The islamists were not that violent and did not initially force the people to convert on the point of sword. One such clan, which perhaps came earliest, migrated northwards and settled in Shravasti, which was a Budhist centre near present Gorakhpur. They acquired the name "Shrivastava". Later on more "Kayasthas" came over and found employment in other places in India. They adopted different surnames, probably, based upon the place of origin in Egypt, profession or place of adopted home.