Constitution of India Constitution of India Ratified 26 November 1949 Date effective January 26, 1950 ; 68 years ago Author(s) B. R. Ambedkar and Drafting committee of the Constituent Assembly of India Signatories 284 members of the Constituent Assembly Purpose To replace the Indian Independence Act The Constitution of India is the supreme law of India . [1] It lays down the framework defining fundamental political principles, establishes the structure, procedures, powers and duties of government institutions and sets out fundamental rights, directive principles and the duties of citizens. It is the longest written constitution of any sovereign country in the world. [Note 1] [2] B. R. Ambedkar , the chairman of the Drafting Committee, is widely considered to be its chief architect. It imparts constitutional supremacy and not parliamentary supremacy , as it is not created by the Parliament but, by a constituent assembly, and adopted by its people, with