The leading BBC foreign affaris reporter and Paris Correspondent chairs a discussion about the fifteen-hundred-year relationship between Christianity and Islam. In 638AD, the Christian Patriarch of the holy city of Jerusalem called the Muslim Caliph's presence an abomination in the sight of God. Christians and Muslims have since regarded each other warily and have silently thought of each other as 'infidels'. Fletcher is the author of The Cross and The Crescent, Wheatcroft is the author of Infidels.