Quercia had accepted another major commission in…
1431 CE
Quercia had accepted another major commission in 1425: the design of the round-arched Porta Magna of the Basilica of San Petronio, the main church of Bologna.
It will keep him busy for a good deal of the last thirteen years of his life and is considered his masterwork.
Each side of the door is flanked, first by a colonette with a spirally wound decoration, then nine busts of prophets and at the end five scenes from the Old Testament, carved into somewhat lower relief.
In the Creation of Adam, he uses the same arrangement as in the Fonte Gaia (in Siena), but in reverse order.
Michelangelo, who will visit Bologna in 1494, will concede that his Genesis in the Sistine Chapel in the Vatican is based on these reliefs.
The architrave above the door contains five reliefs with representations from the New Testament.
The lunette contains three freestanding statues Virgin and Child, Saint Petronius (with a model of Bologna in his right hand) and Saint Ambrose (carved by another sculptor Domenico Aimo in 1510).
Originally this third statue was to represent the papal legate Cardinal Louis Aleman, who had commissioned Quercia in 1425, but this intention had been quickly abandoned after the cardinal was evicted from Bologna.
Quercia relies heavily on the artists of his Bolognese workshop, such as Cino di Bartolo, for assistance in this project.
The first stone of construction of the Basilica had been laid June 7, 1390, when the town council entrusted Antonio di Vincenzo with raising a Gothic cathedral.
In order to make room for this monumental construction, the adjacent Curia of Sancti Ambrosii had been demolished, together with the majority of one of the city’s burgs, including at least eight churches and towers.
Works will last for several centuries: after the completion of the first version of the facade, in 1393 the first pair of side chapels were begun.
The series will be completed only in 1479.
The facing of the main facade remains unfinished: many architects (notably Baldassarre Peruzzi, Vignola, Andrea Palladio and Alberto Alberti) will be commissioned to propose solutions for it, but a definitive one will never be found.