Federigo III King of the Kingdom of Sicily (officially King of Trinacria) from 1355 to 1377 from the Barcelona (in Sicily – Aragonese) dynasty. Date of Birth: 01.09.1341 Country: Italy

1. Reign of Frederick III
2. Early Life
3. Weak Royal Authority
4. Angevin Threat and Civil War
5. Treaty of Aversa
6. Reconciliation with the Papacy
7. Marriages and Succession

Reign of Frederick III

Frederick III ruled the Kingdom of Sicily from 1355 to 1377 as a member of the House of Barcelona (later known as the House of Aragon in Sicily).

Early Life

Born on September 1, 1341, Frederick III was the third son of Peter II, King of Sicily, and Elizabeth of Carinthia. He inherited the throne from his childless brother, Louis, on October 16, 1355.

Weak Royal Authority

Frederick III's reign was marked by a decline in royal authority in Sicily. The instability during his minority and the reigns of his predecessors, along with factional strife among barons, led to the rise of powerful aristocratic families who became virtually independent rulers.

Angevin Threat and Civil War

Opposition to the House of Barcelona existed among the Sicilian nobility (known as the filoangioini), who sought to restore Angevin rule under the terms of the Treaty of Caltabellotta (1302). The Chiaramonte family, with substantial fiefdoms on both sides of the Strait of Messina, supported this faction. In 1360, a Neapolitan army landed in Messina with the backing of the Chiaramonte. Frederick III fled to Catania but was besieged by the Neapolitans. Catalan mercenaries defeated the invading forces, forcing Louis of Taranto and Joan I to abandon Sicily.

Treaty of Aversa

The subsequent war ended with the signing of the Treaty of Aversa on March 31, 1373. Frederick III recognized the Pope and Joan I as his overlords but retained his title as King of Trinacria and lifelong rule over the island. Despite this agreement, it was never fully implemented, and Frederick III's successors refused to surrender control of Sicily to Joan I.

Reconciliation with the Papacy

The Treaty of Aversa reconciled Frederick III with the Pope and lifted the excommunication that had been imposed on his dynasty since 1321. He also adopted the title of Duke of Athens and Neopatria, previously held by younger members of the House of Barcelona.

Marriages and Succession

Frederick III married twice: first to Constance of Aragon (1361-1363) and then to Antonia Balzo (1372-1374). His only legitimate child was his daughter Mary (1363-1401), who succeeded him as Queen of Sicily in 1377.