Saint John was a middle-aged politician who converted to Christianity in prison. After attaining his freedom, in the mid-15th century, he became a friar. At 70, he preached an influential crusade to enlist local peasants to defend Belgrade from invading Ottoman forces.
Armed in many cases with only slings and scythes, they successfully repelled the siege, but John’s amateurish army proved unruly: after they’d won, they defied his orders and ransacked the Turkish camp. Perhaps it was a cruel justice, then, when these victors were ravaged by the plague, dying — including John — only after their city was safe.