During the First Crusade, Frankish armies swept across the Middle East, capturing major cities and setting up the Crusader States in the Levant. A sustained Western conquest of the region appeared utterly inevitable. Why, then, did the crusades ultimately fail?
To answer this question, historian Nicholas Morton focuses on a period of bitter conflict between the Franks and their Turkish enemies, when both factions were locked in a struggle for supremacy over the city of Aleppo. For the Franks, Aleppo was key to securing dominance over the entire region. For the Turks, this was nothing less than a battle for survival -- without Aleppo they would have little hope of ever repelling the European invaders. This conflict came to a head at the Battle of the Field of Blood in 1199, and the face of the Middle East was forever changed.