Maria of Sicily was born on 2 July 1363 as the daughter of Frederick the Simple and Constance of Aragon. Her mother died shortly after her birth, possibly as a result of the childbirth. When Maria was nine, her father remarried to Antonia of Baux, but that marriage remained childless, and Antonia died the following year. Her father was betrothed again, but a third marriage never materialised, and Maria remained his only child and heiress.
Her father died shortly after her 14th birthday and the regency was assumed by a group of barons knows as the “vicars”. Besides the Kingdom of Sicily, she also inherited the duchies of Athens and Neopatria. In 1379 Maria was kidnapped by Raymond of Montcada, a Sicilian nobleman. She was imprisoned for two years at Licata. She was eventually rescued by the Aragonese. She was first taken to Sardinia and later to Aragon, where she was married to Martin the Younger in 1384, who was a son of King Martin of Aragon and Maria de Luna. They returned to Sicily in 1392 with forces to defeat the opposing barons. Maria gave birth to a son in 1394, who was named Peter. Peter was Crown Prince of Sicily until his untimely death in 1400. They never had another child. She and Martin ruled Sicily jointly until Maria’s death in 1401. Her husband repudiated the Treaty of Villeneuve from 1372 and continued to rule Sicily on his own.
Maria is buried in Catania Cathedral, where her sarcophagus can still be seen.
After her husband’s death, he was succeeded by his own father, who by then had no legitimate successors. Sicily was then inherited by Ferdinand I of Aragon, who was a great-grandson of Peter II of Sicily.