Mary of Sicily (c 13701402), Queen of Sicily, was the daughter and heir of Frederick III "The Simple". As she was very young at the time of her father's death, her government was effectively taken over by four baronial families who styled themselves "vicars." In 1390 Mary was taken to Aragon where she was married to Martin "The Younger", the grandson of John II of Aragon. In 1392 Mary and Martin returned with a military force and successfully defeated the opposing barons, ruling jointly until Mary's death in 1402. At that time, Martin repudiated the Treaty of 1372 and ruled Sicily alone.
