The bridge spans the Arno at its narrowest point where it is believed that a bridge was first built in Roman times, when the via Cassia crossed the river at this point. The Roman piers were of stone, the superstructure of wood. The bridge first appears in a document of 996. After being destroyed by a flood in 1117 it was reconstructed in stone but swept away again in 1333 save two of its central piers, as noted by Giovanni Villani in his Nuova Cronica. It was rebuilt in 1345. Giorgio Vasari recorded the traditional view of his day that attributed its design to Taddeo Gaddi — besides Giotto one of the few artistic names of the trecento still recalled two hundred years later. Modern historians present Neri di Fioravanti as a possible candidate. Sheltered in a little loggia at the central opening of the bridge is a weathered dedication stone, which once read Nel trentatrè dopo il mille-trecento, il ponte cadde, per diluvio dell' acque: poi dieci anni, come al Comun piacque, rifatto fu con questo adornamento. The Torre dei Mannelli was built at the southeast corner of the bridge to defend it.