The National Democratic Party (NDP) was a centrist and authoritarian political party that ruled Egypt from 1978 to 2011 under Anwar Sadat and Hosni Mubarak. The party was founded to replace the Arab Socialist Union of Egypt, a left-wing party, and Sadat became the leader of a de facto one-party state dominated by the NDP. The NDP was a moderate centrist party, abandoning the ASU's nationalism and socialism, although it was formally a member of Socialist International from 1989 to 2011. In the Egyptian Revolution of 2011, protests in Cairo's Tahrir Square led to the downfall of Mubarak's NDP government, and the NDP was dissolved and its assets seized by the state.
