New archbishop of Canterbury formally takes office in ceremony at St. Paul's in London

The new Archbishop of Canterbury Justin Welby waves outside St Paul's Cathedral as he poses for the media following his ceremony known as the confirmation of election in London, Monday, Feb. 4, 2013. (AP Photo/Alastair Grant) (The Associated Press)

Justin Welby, centre, former Bishop of Durham, during a ceremony at St Paul's Cathedral, to formally take office as the new Archbishop of Canterbury, Monday, Feb. 4, 2013. Justin Welby was confirmed as the 105th Archbishop of Canterbury at a service under the dome of the cathedral attended by the Archbishop of York, Dr John Sentamu, and seven other senior Church of England bishops. (AP Photo/Toby Melville, Pool) (The Associated Press)

The new Archbishop of Canterbury, Justin Welby with his wife Caroline walks outside St Paul's Cathedral to pose for the media following his ceremony known as the confIrmation of election in London, Monday, Feb. 4, 2013. (AP Photo/Alastair Grant) (The Associated Press)

The new archbishop of Canterbury has formally taken up his post as the leader of the world's 80-million-strong Anglican Communion.

The Most Rev. Justin Welby swore allegiance to the queen as he accepted the position amid prayers for him, his wife Caroline, and their five children.

The election of Welby, a former oil executive, comes at a difficult time for the Anglican Communion, whose global membership includes the U.S. Episcopal Church.

The communion has been riven by bitter disagreements over female bishops and church teachings on gay relationships.

Welby succeeds Rowan Williams, who retired in December after a decade in office.