The Third Crusade of Richard the Lionheart is well known but the build-up to it less so. Downfall of the Crusader Kingdom is a story of intrigue, plot and counter-plot, and the abuse of power culminating in the most decisive battle of the medieval epoch, the Battle of Hattin in 1187. Hattin is one of the few battles in history that can truly be called decisive, and it was a catastrophe for the Crusaders. The leading men of the kingdom of Jerusalem, including the Knights Templar and the Hospitallers, were trapped in an arid wasteland, without water and surrounded by hostile forces. The battle ended with thousands of them being taken prisoner. It was the culmination of a series of events that had been progressively leading the kingdom of Jerusalem down the road to oblivion. It was partly the resurgence of the Muslim Middle East and the rise of Saladin that led to the loss of Jerusalem, but there was another equally dangerous element at work - the enemy within. W B Bartlett brings to life the bitter infighting and political battles which ultimately led to the disaster at Hattin and the downfall of the Crusader kingdom.