According to legend Rosalia was born in 1130 of a Norman noble family that descended from Charlemagne. A very pious young lady, she retired to live as a hermit in a cave on the Monte Pellegrino, where she died in 1166. Nobody knew anything about her demise.
In 1624 a horrible plague haunted Palermo, and during this hardship Santa Rosalia appeared first to a sick woman, then to a hunter to whom she indicated where her remains were to be found. She ordered him to bring her bones to Palermo and have them carried in procession through the city.
The hunter climbed the mountain and found her bones in the cave as described. He did what she had asked in the apparition, and after the procession the plague ceased. After this Santa Rosalia would be venerated as the patron saint of Palermo, and a sanctuary was built in the cave where her remains were discovered.
The celebration, called the festino, is still held each year on July 15. It is still a major social and religious event in Palermo. Also 4 of September there is an event related to the festino and S. Rosalia; a tradition of walking on nude feet from down (Palermo) to up Monte Pellegrino.