Since the birth of the Republic in 1948 the constitution has undergone five major revisions, each signifying the emergence of a new republic, the present republic being the sixth. President Lee Myung-bak of the Grand National Party was elected in February 2008. Korean presidents are elected for single five-year terms. Unlike the U.S. government the president is not the commander in chief of the army. The National Assembly (Gukhwe) has 299 members elected for a four year term: 243 members in single-seat constituencies and 56 members elected by proportional representation. The main political parties in South Korea are the United Democratic Party (evolved from the Uri Party), the Grand National Party (GNP), the Democratic Labor Party (DLP), and the Democratic Party (DP).