Enzio, Or Entins, a natural son of Frederick II., emperor of Germany, born in 1224 or 1225, died in Bologna, March 14 or 15, 1272. He was handsome, accomplished, and chival-ric, and took a distinguished part in the contests of hi<s father with the Guelphs. At the age of thirteen he accompanied him to the battle of Cortenuova, and about two years later his father caused his marriage with Adelasia, marchioness of Massa, the widow of Waldo-Visconti, and the heiress of important possessions in Italy. On this occasion he was created king of Sardinia, but it was only a nominal dignity. A more substantial one conferred on him by the emperor was that of governor general of Lombardy and commander of the German troops against the Milanese. Gregory IX. excommunicated Frederick in March, 1239; the pope's anger increased the ardor of Enzio, and he conquered for his father many towns in Umbria. As commander of the emperor's naval force in 1241, he defeated, in conjunction with the Pisan fleet, the Genoese in the vicinity of Leghorn, near the island of Meloria (May 3), after a protracted engagement.

A great number of prelates were on board the Genoese galleys, about to attend, in spite of the emperor's remonstrance, a council convoked at Rome by Gregory. All these prelates, about 100 archbishops and bishops and three legates of the pope, were captured; the total number of prisoners was estimated at 4,000. The booty taken from the Genoese comprised a large amount of money, and in token of this success the prelates were removed to prison in chains of silver. After this and other victories over the Guelphs, the Ghibel-lines were defeated, May, 26, 1249, in the bloody battle on the Fossalta. Enzio being captured, the Bolognese condemned him to perpetual imprisonment, and refused to release him, although the emperor was ready to pay any ransom. He continued in prison 23 years, surviving the sons and grandsons of Frederick, who all met with violent deaths.