One of the founder-members of the All India Muslim League, A. K. Fazlul Haq fought for the rights of Muslims. From 1916 to 1921, he was the President of the League. He played a significant role during negotiations between the Congress and the League over the Lucknow Pact in 1916.

He represented the League at the Round Table Conferences (1930-33). In 1937, he left the Muslim League and launched the Krishak Praja Party. After the 1937 elections, he entered into a coalition with the Muslim League and formed a Government in Bengal. From 1938-43, he worked as Chief Minister of Bengal. After inde­pendence, he settled in Dacca.