William David Trimble, Baron Trimble, PC is a British politician who was the first First Minister of Northern Ireland from 1998 to 2002, and the leader of the Ulster Unionist Party (UUP) from 1995 to 2005. He was also the Member of Parliament for Upper Bann from 1990 to 2005 and the Member of the Legislative Assembly (MLA) for Upper Bann from 1998 to 2007. In 2006, he was made a life peer in the House of Lords and a year later left the UUP to join the Conservative Party.
