The Constitution of India was adopted on November 26, 1949 and came into effect on January 26, 1950. It was drafted by the Constituent Assembly which was elected by provincial assembly members. Key figures in drafting the constitution included Dr. B.R. Ambedkar, Jawaharlal Nehru, and Sardar Vallabhbhai Patel. The current constitution consists of a preamble, 25 parts, 463 articles, 12 schedules, 2 appendices and 97 amendments. It establishes a federal structure with a strong unitary bias, parliamentary democracy, and an independent judiciary.