Following the 1952 revolution, Egypt declared itself a republic, and in 1958 it merged with Syria to form the United Arab Republic, which was dissolved in 1961. Egypt fought several armed conflicts with Israel in 1948, 1956, 1967 and 1973, and occupied the Gaza Strip intermittently until 1967. In 1978, Egypt signed the Camp David Accords, which recognised Israel in exchange for its withdrawal from the Sinai. After the Arab Spring, which led to the 2011 Egyptian revolution and overthrow of Hosni Mubarak, the country faced a protracted period of political unrest; this included the election in 2012 of a brief, short-lived Muslim Brotherhood-aligned Islamist government spearheaded by Mohamed Morsi, and its subsequent overthrow after mass protests in 2013.