Just south of the Mercato Nuovo is a well-preserved pocket of medieval city. The Palagio di Parte Guelfa at Piazza di Parte Guelfa was the 13th-century headquarters of the Guelph party ('palagio' was the Florentine word for a building in between a tower house and a palazzo) and often the real seat of power in the city. They gleefully paid for the building with the profits from properties confiscated from the Ghibellines.
As Machiavelli wrote
This Parte Guelfa abused its powers exceedingly for party purposes, and the Parte Guelfa Capitani became more feared than the Signoria itself, and behaved most insolently towards it.'
So by the late 15th century it was dissolved. Before then, Brunelleschi added a hall on the top floor, now known as the Salone Brunelleschi, with a coffered ceiling by Giorgio Vasari. It also has a lunette by Luca della Robbia.
Repaired after damage in the Second World War, the Palagio now houses the organization of the Calcio Storico, while the Salone Brunelleschi often hosts special events. You can pop in to visit one of the city's municipal libraries.
Next door is the guildhall of the silk makers, the 14th-century Palazzo dell’Arte della Seta, still bearing its bas-relief emblem, or ‘stemma’, of a closed door, the age-old guild symbol.
Just around the corner from the Guelph Palace, take Via Pellicceria to see a fine ensemble of medieval buildings on the tiny square near Via delle Terme, where Roman Florentia kept her baths.
Piazza di Parte Guelfa, end of Via Pellicceria
Libary Hours Sept-mid July Mon-Fri 9am-10pm; Sat 9am-1pm; mid July-Aug Mon-Sat 9am-1pm.
Images by: Sailko, GNU Free Documentation License