Callixtus III
Alfonso de Borja · 1455 – 1458
A Borgia pope who devoted his pontificate to organizing a crusade against the Ottoman Turks after the fall of Constantinople.
Alfonso de Borja was a Spanish canon lawyer who had spent decades in quiet ecclesiastical service before being elected pope in 1455 at the age of seventy-seven. The fall of Constantinople two years earlier consumed him. He sold papal silverware, taxed the clergy, and poured everything into organizing a crusade. The results were mixed: a small fleet won a victory on the Aegean, and John Hunyadi's forces lifted the siege of Belgrade in 1456, a genuine turning point that saved Central Europe from Ottoman expansion. Callixtus ordered church bells rung at noon to call the faithful to pray for the crusaders, a custom that persists. He also posthumously retried Joan of Arc and declared her innocent. His pontificate was marred by nepotism, including the advancement of his nephew Rodrigo, the future Alexander VI.
The Noon Bell
Callixtus ordered that church bells ring at noon across Christendom so people would stop and pray for the defense of Belgrade. The siege was lifted. The bells kept ringing. The Angelus prayer that Catholics still say at noon traces back to this moment.
Justice for Joan
Twenty-five years after Joan of Arc was burned at Rouen, Callixtus authorized a retrial that found her innocent and declared her original trial fraudulent. It was the right thing done too late, but it was still the right thing.