Assamese literature its roots in the Eastern dialect. The modern Assamese period began with the publication of the Bible in Assamese prose by the American Baptist missionaries in 1819. The currently prevalent standard Asamiya has its roots in the Sibsagar dialect of Eastern Assam. As mentioned in Bani Kanta Kakati's "Assamese, its Formation and Development" (1941, Published by Sree Khagendra Narayan Dutta Baruah, LBS Publications, G.N. Bordoloi Road, Gauhati-1, Assam, India) – " The Missionaries made Sibsagar in Eastern Assam the centre of their activities and used the dialect of Sibsagar for their literary purposes". The American Baptist Missionaries were the first
Assamese alphabet said to develop proto-Assamese shapes by the 13th century. In the 18th and 19th century, the Assamese script could be divided into three varieties: "Kaitheli" (also called "Lakhari" in Kamrup region, used by non-Brahmins), "Bamuniya" (used by Brahmins, for Sanskrit) and "Garhgaya" (used by state officials of the Ahom kingdom)—among which the "Kaitheli" style was the most popular, with medieval books (like the "Hastir-vidyrnava") and sattras using this style. In the early part of the 19th century, Atmaram Sarmah designed the first Assamese script for printing in Serampore, and the Bengali and Assamese lithography converged to the present standard that