[4] Dr. Bidhan Chandra Roy in 1950 became the first formal chief minister of West Bengal after the implementation of the Indian Constitution.
A period of political instability followed thereafter—West Bengal witnessed three elections, four coalition governments and three stints of President's rule between 1967 and 1972—before Siddhartha Shankar Ray of the INC served a five-year term.
[5] The landslide victory of the Communist Party of India (Marxist)-led Left Front in the 1977 election began Jyoti Basu's 23-year continuous reign as chief minister.
[6] Basu's successor Buddhadeb Bhattacharya continued the communist rule in West Bengal for another decade, when the Left Front was defeated in the 2011 election by the Trinamool Congress, thereby ending the 34-year long rule of the Left Front government, a fact that was noted by the international media.
Sworn in on 20 May 2011, Trinamool Congress leader Mamata Banerjee is West Bengal's incumbent chief minister, the first woman to hold the office.