Basilica of San Petronio

The Basilica of San Petronio is Bologna's largest church, although the archbishop's seat is in Bologna Cathedral. The city council commissioned this basilica. After the people of Bologna expelled the papal legates and regained broad self-government in thirteen seventy-six, the council decided to build a civic church on the main square. The first stone was laid in thirteen ninety.

The church was dedicated to Petronius, the fifth-century bishop of Bologna, whom the townspeople venerated as their chief patron saint. Little reliable information about him has survived. For the medieval Commune of Bologna, what mattered was that he was a local Bolognese saint, connected with the city's fate. That is why his basilica was built beside the palace of the Commune, where the city's main ceremonies took place.

This connection between church and palace proved useful in fifteen thirty. Pope Clement VII was trying to contain Charles V, the elected emperor of the Holy Roman Empire, in Italy. Clement allied himself with Charles's opponents, but lost the war. In fifteen twenty-seven, the imperial army, which had gone unpaid for months and been left without effective command, captured and sacked Rome. Clement fled to Castel Sant'Angelo, became a prisoner there, and paid for his release.

Charles needed a coronation at the pope's hands. Clement needed peace with the man whose soldiers had nearly cost him his throne and his life. They made an agreement, after which Charles himself asked for the coronation to be held in Bologna rather than Rome, where his name was associated with the recent sack.

On February twenty-second, fifteen thirty, in the chapel of the palace of the Commune, Clement placed the Iron Crown of Lombardy of the Italian kings on Charles. For the next ceremony, by the pope's order, a long wooden walkway was built from the palace, across the square, to the high altar of the Basilica of San Petronio. It allowed the members of the procession to pass above the gathered crowd directly into the church.

On February twenty-fourth, Charles put on the imperial mantle in the Chapel of San Abbondio and knelt before Clement. The pope blessed the sword, personally girded Charles with it, handed him the scepter and orb, and then placed the imperial crown on him. Three years earlier, Clement had been fleeing from Charles's army; now his hands completed this man's coronation.

Charles received public papal recognition of his imperial title. Clement secured the return of his Medici family to Florence, as provided for in the agreement: after the siege, the Florentine Republic fell. No subsequent emperor was ever crowned by a pope.

The wooden walkway was dismantled after the festivities. An open square again lies between the palace of the Commune and the Basilica of San Petronio. Inside the basilica, an inscription about the coronation has survived on the enclosure of the Chapel of San Abbondio—it was in this very chapel that Charles V put on the imperial mantle.