Sirima Ratwatte Dias Bandaranaike, commonly known as Sirimavo Bandaranaike, was a Sri Lankan stateswoman who thrice served as Prime Minister of Sri Lanka from 1960 to 1965, from 1970 to 1977, and from 1994 to 2000. She was the first woman in the world to be elected prime minister in 1960. A chairperson of the Sri Lanka Freedom Party (SLFP) from 1960 to 1994, she pursued socialist economic policies and promoted Sinhalese Buddhist nationalism. Bandaranaike also served as chairperson of the Non-Aligned Movement (NAM) from 1976 to 1977, becoming the first woman to lead the organisation. Her combined tenure of 17 years and 211 days in office, spanning three non-consecutive terms, makes her the longest-serving prime minister in Sri Lankan history.