Before the coming of British East Indian Company to Assam, the Ahom dynasty ruled Assam for long 600 years. They adopted a special policy towards the neighboring hill tribes. The hill tribes were depended on Assam for their livelihood. the Ahom rulers established “Duars” khats for entry and imposed taxes on hill tribes. The Ahom rulers started “Posa” system to maintaining relation with hill tribes. The policy was very successful to maintain good relation with them.
Raouf Ahmed (Thu,) studied this question.