Today, 59 years ago, on January 11, 1966 (Lunar Calendar, December 20, 1965), Indira Gandhi became Prime Minister of India. India's first female Prime Minister, Indira Gandhi, and India's first female Prime Minister, Shastri, died of a heart attack following the conclusion of the Tashkent Agreement with Pakistani President Ayyub Khan. On December 19, Nehru's daughter, Indira Gandhi, was elected as the leader of the ruling party, India's prime minister. She promised to support the Tashkent Agreement.