Purchase includes free access to book updates online and a free trial membership in the publisher's book club where you can select from more than a million books without charge. Chapters: Frederick Ii, Holy Roman Emperor, Sicilian School, Manfred of Sicily, Stefano Protonotaro Da Messina, Enzio of Sardinia, Giacomo Da Lentini. Excerpt: King Enzio imprisoned in Bologna, from a medieval manuscript. Tombstone in the Basilica of San Domenico, Bologna . Enzio or Enzo (Italianisation of Heinz, diminutive of Heinrich ) (c. 1218 1272) was an illegitimate son of Emperor Frederick II and King of Sardinia . Life Enzio was an illegitimate son of Frederick II by a certain Adelaide. It is speculated that she was Adelaide of Urslingen. He was the eldest of the illegitimate sons of the emperor, and allegedly the favourite one . He had a pleasant personality and a strong physical resemblance to his father. He fought in the wars between his father, the pope, and the Northern Italian communes. When Ubaldo of Gallura died in 1238, the Doria family of Genoa, in order to secure the Giudicato of Logudoro from Pisan domination, convinced the emperor to marry Enzio to Ubaldo's widow, Adelasia of Torres . By marrying her, Enzio would accede to half of the island of Sardinia jure uxoris . He was created a knight in Cremona and granted the title "King of Sardinia." He travelled to the island to marry Adelasia in October that year. In July 1239, he was assigned as imperial vicar general in Lombardy, as well as General-Legate in Romagna, and left Sardinia never to return. In 1241, he took part in the capture of a papal fleet at Giglio Island in the Tyrrhenian Sea . His first successful move as military leader was the reconquest of Jesi, in the Marche, which was Frederick's birthplace. Later he was captured in a skirmish against the Milanese at Gorgonzola, but soon released. In 1245 or 1246 his marriage was annulled. In 1247, he took part in the unsuccessful siege of Parma . He contin...