The Bargello National Museum is found in the former Palazzo del Capitano del Popolo, built in 1255 and embellished in 1287 with the beautiful loggia which opens onto the courtyard. Here, the Podestà called the representatives of the Art and the Corporazioni (guilds) to meetings. The tower, predating the building, once housed the "Montanina", the bell that tolled of gather Florence's population in time of war or siege. In 1502, the palace became the seat of the Consiglio di Giustizia e della Polizia, headed by the Bargello or chief of police. Until 1857, the palace was also used as a prison. Following restoration by the architect Francesco Mazzei, in 1886 the Bargello was transformed into a museum of sculpture and examples of the "minor arts". Some of the greatest sculptures of the Renaissance have found their home here: masterpieces by Donatello, Verrocchio, Michelangelo, and Cellini. Over time, prestigious collections of small bronzes, majolica-ware, wax pieces, enamelled works, medals, ivories, amber, tapestries, seals, and fabrics, some grom the Medici collections and some from the Medici collections and some from private donations, have enriched the museum's holdings.