The first pater patriae, Bishop Saint Zanobi, encouraged the resistance of the Florentines against the invasion of the Ostrogoths of Radagaisus, who besieged the city but were providentially defeated by the arrival of Stilicho, the great general of the Emperor Honorius. On the day of victory (according to tradition) Saint Reparata of Caesarea of ​​Palestine was remembered and for this reason it was decided to dedicate a parish church to the north as a sign of gratitude, the Church of Santa Reparata which a few centuries later became the cathedral in place of the already existing Baptistery of San Giovanni, then simply a church, often indicated as the oldest building in Florence that has maintained its original structure.

Thanks to the victory, the entire population was definitively converted to Christianity and the ancient patron, the God Mars, was gradually replaced by Saint John the Baptist.