Who was the chairman of constitution drafting committee of Constituent Assembly?

Dr. B R Ambedkar is one of the best legal minds produced by modern India. He singlehandedly struggled for the upliftment of the dalits and downtrodden low castes, giving them social equality, self respect and political empowerment. His contribution as chairman of constitution drafting committee of Constituent Assembly  as earned him the epithet of “Father of Indian Constitution”.