Simplify the following text for a Grade 12 native English-speaking person.
Original: He served as Leader of the Ulster Unionist Party ( UUP ; 1995 â `` 2005 ) , was the first First Minister of Northern Ireland ( 1998 â `` 2002 ) , and was a Member of the British Parliament ( 1990 â `` 2005 ) .
Simplified: He was Leader of the Ulster Unionist Party ( UUP ; 1995 â `` 2005 ) , the first First Minister of Northern Ireland ( 1998 â `` 2002 ) , and was a Member of the House of Commons ( 1990 â `` 2005 ) .