The Crusades by Thomas Asbridge (Author)

Nine hundred years ago, a vast Christian army, summoned to holy war by the Pope, rampaged through the Muslim world of the eastern Mediterranean, seizing possession of Jerusalem, a city revered by both faiths. Over the two hundred years that followed, Islam and Christianity—both firm in the belief that they were at God's work—fought for dominion of the Holy Land, clashing in a succession of chillingly brutal wars: the Crusades.