Enzo was an illegitimate son of the Hohenstaufen emperor Frederick II, who appointed him 'King of Sardinia' in 1238. He played a major role in the wars between Guelphs and Ghibellines in the Imperial kingdom of Italy, and was captured by his enemies in 1249. He remained imprisoned in Bologna until his death.
The captured King Enzio of Sardinia (here called "Rex Hentius") in the initial to Amor mi fa sovente in the song manuscript Canzoniere Palatino, created in Pistoia at the end of the 13th century
Coat of arms of Enzo of Sardinia
Posthumous epitaph from 1731 by Giuseppe Maria Mazza in the Basilica of San Domenico, Bologna
Frederick II, Holy Roman Emperor
Frederick II was King of Sicily from 1198, King of Germany from 1212, King of Italy and Holy Roman Emperor from 1220 and King of Jerusalem from 1225. He was the son of emperor Henry VI of the Hohenstaufen dynasty and Queen Constance of Sicily of the Hauteville dynasty.
A gold augustalis bearing Frederick's effigy. Legend: c(a)esar aug(ustus) imp(erator) rom(anorum)
The birth of Frederick on the market square of Jesi from the Nuova Cronica, Biblioteca Apostolica Vaticana, ms. Chigi L. VIII.296 (cat. XI.8)
Constance handing her son over to the care of the duchess of Spoleto, the wife of Conrad of Urslingen, from the Liber ad honorem Augusti by Peter of Eboli
Seals used by Frederick as Emperor (ed. Otto Posse 1909): 1: first imperial seal (1221–1225), 2: second imperial seal (1226), 3: third imperial seal, addition of the title of King of Jerusalem (1226–1250) 4: seal used in 1221 and 1225, 5: first seal as King of Jerusalem (1233).