Callixtus III

Constantinople fell to Mehmed II in May 1453, and the shock ran through Latin Christendom for a generation. Alfonso de Borja was elected pope in April 1455 with the recovery of the city as the declared purpose of his pontificate, and he pursued it with a single-mindedness his contemporaries found either admirable or obsessive. He sold papal property and plate, cut the expenditure of the curia, had a fleet built at Ostia, and sent legates across Europe preaching a crusade to rulers who had, almost without exception, more pressing quarrels at home.

The one substantial result came in the summer of 1456 and not at Constantinople. Ottoman forces moved up the Danube to besiege Belgrade, the gateway to Hungary, and the defence was organized by the Hungarian commander John Hunyadi with a large force of poorly armed volunteers raised by the Franciscan preacher John of Capistrano, who had been sent out by the pope. The siege was broken in July. Callixtus had already ordered church bells rung at noon across Christendom as a call to pray for the defenders, and the noon bell is often said to commemorate the victory afterwards, though the order preceded the news.

He did not live to see anything further. The crusade dissolved after his death in 1458, and the Ottoman advance into the Balkans continued. What the pontificate demonstrated was the limit of papal power to move fifteenth century Europe: the money, the preaching and the legates were real, and they produced one successful defensive battle rather than the reconquest he had promised.

Joan of Arc was condemned as a relapsed heretic and burned at Rouen in 1431 by a court operating under English control. Her mother Isabelle Romee and her brothers petitioned Rome for a review, and in 1455 Callixtus III authorized an inquiry into the trial. The proceedings took evidence from more than a hundred witnesses across France, including men who had sat on the original court, and in July 1456 the verdict of 1431 was declared null on grounds of procedural fraud and irregularity. The nullification did not declare Joan a saint, a step that waited until 1920, but it removed the sentence of heresy that had stood over her name for a quarter of a century.

The other story attached to his reign is not true. Nineteenth century writers, following a loose reading of Bartolomeo Platina's papal history, circulated the claim that in June 1456 Callixtus excommunicated the comet now known as Halley's as an agent of the Turks. What the sources actually record are prayers and processions ordered against the Ottoman advance at a moment when a comet happened to be visible, and a papal bull of that content has never been produced.

The pontificate's longest consequence was neither of these. In 1456 Callixtus made his nephew Rodrigo Borgia a cardinal and, the following year, vice chancellor of the church. Rodrigo held that office for thirty-five years and was elected pope as Alexander VI in 1492, so the family fortune that made the Borgia name a byword for Renaissance papal corruption begins with an aged Valencian pope's ordinary preference for his own relatives.