The Baptistery in Pistoia and Saint Ambrose’s octagon
Many baptisteries are octagonal in shape, including the one in Pistoia, dedicated to Saint Giovanni in Corte and dating back to the second half of the 14th century.
Most experts believe that the eight-side polygonal floor plan of these holy structures, once built near churches, was inspired by the Bishop of Milan, Saint Ambrose, who promoted the construction of the Baptistery of San Giovanni alle Fonti, in Milan, next to the ancient Basilica dedicated to the virgin martyr Saint Tecla, in what now is Piazza Duomo.
Legend has it that Ambrose had written a poem, which has reached us thanks to an 8th-century codex but at the time was engraved around the baptismal font where the bishop baptized Saint Augustine in 387, and perhaps on the eight walls of the surrounding building, one couplet on each side. The short epigraphic work stated:
“[…] It was right for the room of the Sacred Baptistery to have eight sides, because people were granted true salvation when, at dawn on the eighth day, Christ rose from the dead.”
After almost one thousand years, Pistoia built one of the last imposing baptisteries of the Middle Ages (others are in Parma, Cremona, Florence, Siena and Ascoli Piceno).
Here is the octagonal wonder, in all of its Italian gothic style.