How a Pirate Became Pope

How did Baldassarre Cossa, the pirate pope, become the leader of the Catholic Church? From 1410-1415, Cossa reigned as Pope John XXIII, but he wasn't the only pope at the time. In fact, Cossa was one of three popes who struggled to rule over the church. Known as the Western Schism, the split lasted from 1378-1417, and multiple popes declared supremacy but refused to step down. In the chaos, the former pirate seized power, literally placing the stole of Peter on his own shoulders.