Reading history should not only mean the chronological presentation of development during various kings and their dynasties, but should also try to establish the developments with their causative factors. I always was interested to kind out the root cause of creation of Bangladesh with nearly ninety percent Muslims as a country for the Bengali speaking people of the Indian sub-continent. In the past a Bengali person appeared to represent a Bengali speaking Hindu not only to the Indians but also to the then West Pakistani people. The later evolutionary factors which resulted in creation of Bangladesh as homeland for the Bengali Muslims in presented herein in the research for the M. A thesis.