2-332-317 - Vivienne Sharp/Heritage Images

River Tigris from the doorway of the ruined Caliph's Palace, Samarra, Iraq, 1977. Samarra was made the capital of the Muslim Caliphate in 836 by Caliph Al-Mu'tadid. It remained the capital of the Islamic world until superseded by Baghdad in 892. The city of Samarra began a decline which accelerated when the River Tigris altered its course in the 13th century.