For a few years Sicily enjoyed peace, and the kingdom was reorganized. But on the descent of the emperor Henry VII., Frederick entered into an alliance with him, and in violation of the pact of Caltabellotta made war on the Angevins again (1313) and captured Reggio. He set sail for Tuscany to cooperate with the emperor, but on the latter's death (1314) he returned to Sicily. Robert, who had succeeded Charles II. in 1309, made several raids into the island, which suffered much material injury. A truce was concluded in 1317, but as the Sicilians helped the north Italian Ghibellines in the attack on Genoa, and Frederick seized some Church revenues for military purposes, the pope (John XXII.) excommunicated him and placed the island under an interdict (1321) which lasted until 1335. An Angevin fleet and army, under Robert's son Charles, was defeated at Palermo by Giovanni da Chiaramonte in 1325, and in 1326 and 1327 there were further Angevin raids on the island, until the descent into Italy of the emperor Louis the Bavarian distracted their attention. The election of Pope Benedict XII. (1334), who was friendly to Frederick, promised a respite; but after fruitless negotiations the war broke out once more, and Chiaramonte went over to Robert, owing to a private feud. In 1337 Frederick died at Paternione, and in spite of the peace of Caltabellotta his son Peter succeeded. Frederick's great merit was that during his reign the Aragonese dynasty became thoroughly national and helped to weld the Sicilians into a united people. BIBLIOGRAPHY.--G. M. Mira, _Bibliografia Siciliana_ (Palermo, 1875); of the contemporary authorities N. Speciale's "Historia Sicula" (in Muratori's _Script. rer. ital._ x.) is the most important; for the first years of Frederick's reign see M. Amari, _La Guerra del Vespro Siciliano_ (Florence, 1876), and F. Lanzani, _Storia dei Comuni italiani_ (Milan, 1882); for the latter years C. Cipolla, _Storia delle signorie italiane_ (Milan, 1881); also Testa, _Vita di Federigo di Sicilia_. (L. V.)