Amongst native-born Assamese during the decade there was a serious decrease in Nowgong and some other districts, due to kalaazar and other diseases.
Hinduism has also impressed its language upon the province, and the vernacular Assamese possesses a close affinity to Bengali, with the substitution of s for the Bengali ch, of a guttural h for the Bengali h or sh, and a few other dialectic changes.
In medieval history, the Assamese were known to the Mussulman population as a warlike, predatory race,- who sailed down the Brahmaputra in fleets of innumerable canoes, plundered the rich districts of the delta, and retired in safety to their forests and swamps.
During the civil wars between the sons of Shah Jahan, the king of Assam renewed his predatory incursions into Bengal; upon the termination of the contest, Aurangzeb determined to avenge these repeated insults, and despatched a considerable force for the regular invasion of the Assamese territory (1660-1662).
The Assamese are an interesting race, of distinct origin from the neighbouring Bengalis.