On February 17, 1949, Chaim Weizmann was sworn in as Israel’s first president. He was elected to the post by the Knesset, the Israeli parliament, which was sitting in Jerusalem at the time. Chaim Weizmann received 83 votes in the first presidential election held in the Knesset a few days earlier, while his only opponent, Joseph Klausner, received 15.
As President-elect, Weizmann appointed David Ben-Gurion as Prime Minister, that is, the Prime Minister of Israel (Ben-Gurion was at the head of Mapiy, Israel’s leading political party). At the time he became President of Israel, Weizmann was 74 years old and a highly respected scholar. As an organic chemist, he gained merit among British politicians during the First World War through his process of producing chemicals potentially important for the production of explosives and fuels. Its industrial fermentation process could produce acetone and a variety of other organic compounds from simple and readily available substances.