In the week when Prince Charles has drawn attention to violence against Christians in the Middle East, William Dalrymple says it's time to remember the "old and often forgotten co-habitation of Islam and Christianity".

"Christmas time is perhaps the proper moment to remember the long tradition of revering the nativity in the Islamic world. ...There are certainly major differences between the two faiths, not least the central fact, in mainstream Christianity, of Jesus' divinity. But Christmas - the ultimate celebration of Christ's humanity - is a feast which Muslims and Christians can share without reservation.".