 After leading Israel during the 1948 Arab–Israeli War, Ben-Gurion was elected Prime Minister of Israel when his Mapai (Labour) party won the largest number of Knesset seats in the first national election, held on 14 February 1949.He remained in that post until 1963, except for a period of nearly two years between 1954 and 1955.As prime minister, he oversaw the establishment of the state's institutions.