Built in 1245 as an extension to the older Palazzo del Podestà , the Palazzo Re Enzo takes its name from Enzo of Sardinia, illegitimate son of Holy Roman Emperor Frederick II. Captured by Bolognese troops at the Battle of Fossalta in 1249, he was held here in honourable captivity until his death in 1272 — 23 years that he reportedly filled with poetry, music, and fathering at least one daughter with a local woman.
The current Gothic appearance dates from a heavy restoration in 1905; the original building was simpler. Today it is used mostly for temporary exhibitions and civic events. The double-loggia courtyard with its external staircase is worth a look even when nothing is on.