Maria, Queen of Sicily

Maria (2 July 1363 – 25 May 1401) was Queen of Sicily and Duchess of Athens and Neopatria from 1377 until her death.

Born in Catania, she was the daughter and heir of Frederick the Simple by his first wife Constance of Aragon. As she was very young at the time of her father's death in 1377, her government was effectively taken over by four baronial families who styled themselves "vicars".

The regent named by Maria's father, Artale Alagona, was initially forced to form a government with other three Vicars, including Francesco II count of Ventimiglia, Manfredi III Chiaramonte, count of Modica, and Guglielmo Peralta, count of Caltabellotta, with a parity of exponents of the "Italian" and "Aragonese" parties. However, the four men ruled in their separate baronial lands alone. In 1379 she was kidnapped by count William Raymond of Montcada, Sicilian nobleman and member of the Aragonese House of Montcada, to prevent her marriage with Giangaleazzo Visconti, Duke of Milan, and imprisoned for two years at Licata. Montcada's move had been approved by her grandfather King Peter IV of Aragon. In 1382 Maria was rescued by an Aragonese fleet; she was taken first to Sardinia, then, in 1384, to Aragon, where she was married to Martin the Younger, the grandson of Peter IV (1389).

In 1392 Maria and Martin returned with a military force and defeated the opposing barons, ruling jointly until Maria's death in 1401. At that time, Martin repudiated the Treaty of Villeneuve (1372) and ruled Sicily alone. She also survived their only son, Peter (1398–1400). The kingdom remained without a crown prince and it caused a succession crisis for Martin, who ruled by right of his wife. Frederick the Simple named his illegitimate son, William, Count of Malta, as heir presumptive in this case of the extinction of his daughter's line; although William died in c. 1380, he had a daughter, Joan, wife of the Sicilian nobleman Pietro di Gioeni, but she must not have contested her uncle's claim since Martin continued to rule until his death.

Maria of Sicily died at Lentini in 1401.