After the establishment of the State of Israel, Yitzhak Shamir worked for Israel's security service, the Mossad from 1955-1965. He joined the Herut political party in 1969. He was elected to Israel's parliament, the Knesset, in 1973 as a member of political party Likud. He was the Prime Minister of Israel from 1983-1984 and from 1986-1992. He was the country’s second longest-serving prime minister after David Ben-Gurion.