Yale professor R. Howard Bloch tells the story of Louis IX's crusading career through the eyewitness chronicle of Jean de Joinville, part of his course The Age of Cathedrals. He covers Louis's piety, the secret staircase meetings with Queen Margaret conducted under Blanche of Castile's watch, and the king's decision to take the cross after a near fatal illness. The lecture turns to the Seventh Crusade itself: Louis leaping from his boat at Damietta in full armor to wade ashore under fire, the disastrous battle of Al Mansura, his capture and ransom, and his stubborn refusal to leave the Holy Land afterward. Bloch uses these episodes from Joinville's account to build the case medieval writers made for Louis's sanctity, showing how a king's battlefield choices became evidence of holiness. It is a short, focused look at how crusading memory shaped the image of a saintly ruler.