ROME Associated Press POPE Benedict XVI has presided over a ceremony in a Rome church with the Archbishop of Canterbury, saying he hopes their presence together will spur both Catholics and Anglicans to pray and work for unity. Benedict led a vespers service Saturday evening at which both he and Rowan Williams, the spiritual leader of the world's Anglican Communion, gave homilies. The two held private talks at the Vatican earlier Saturday, but no details were released. While the pope has made Christian unity a theme of his papacy, he has also created tensions with Williams. In 2009, Benedict issued an unprecedented invitation to Anglicans to become Catholics in groups or as parishes, just as many traditional Anglicans were upset by their church's ordination of women and gay bishops.