 On 17 December 2001, Harper was elected Bishop of Connor by the Episcopal Electoral College.He was consecrated on 18 March 2002 at St Anne's Cathedral, Belfast, and enthroned in Christ Church Cathedral, Lisburn, on 25 April 2002.On 10 January 2007, the 11 bishops of the Church of Ireland elected him the 104th Archbishop of Armagh and Primate of All Ireland, in succession to Archbishop Robin Eames.