Terry Jones hosts this look at the four major medieval Crusades, tracing two centuries of holy war between Christian Europe and the Muslim Middle East. The series opens with Pope Urban II's call to arms in 1095 and follows the campaigns through the capture of Jerusalem, the rise of Saladin, and the eventual collapse of the Crusader states. Jones travels to the actual battlegrounds and fortresses, walking the walls of cities that changed hands repeatedly over the period, while historians and reenactors fill in the tactics, sieges, and massacres that defined each campaign. The narration does not treat the Crusaders as simple heroes or villains, weighing religious conviction against plunder, politics, and the brutal treatment of both Muslim and Jewish populations along the way. Battle reenactments and location filming in the Middle East and Europe give the campaigns a physical sense of place, from desert marches to castle sieges, while the throughline stays on how these wars still echo in the region's politics today.