Saint Rosalia (1130–1166), also called La Santuzza or "The Little Saint", is the patron saint of Palermo.

According to legend, Rosalia was born from a Norman noble family that claimed descent from Charlemagne. Devoutly religious, she retired to live as a hermit in a cave on Mount Pellegrino, where she died alone in 1166. Tradition says that she was led to the cave by two angels. On the cave wall she wrote "I, Rosalia, daughter of Sinibald, Lord of Roses, and Quisquina, have taken the resolution to live in this cave for the love of my Lord, Jesus Christ."

"Our Lady of the Letter" is one of the names used by the Catholic religion in the veneration of Mary, Mother of Jesus The tradition, using a statement of historical Lucio Flavio Destro, said that St. Paolo, arrived at Messina to preach the Gospel, found the people willing to leave converted. Soon, many people accepted the invitation to convert to Christianity and, in 42, when Paul was ready to return to Palestine, some of the inhabitants of Messina asked to accompany him to know Our Lady. So a delegation went in Palestine with a letter, in which many citizens who converted to Christianity, professed their faith and seek the protection of Mary. Maria received them and sent back a letter, written in Hebrew, rolled and tied with a lock of her hair. The delegation returned to Messina on September 8, 42 bringing the important missive : Mary praised their faith , said to appreciate their devotion and assured them his perpetual protection. So terminates the letter: "Vos et Ipsam civitatem benedicimus", that is "I bless you and your city". The text is now written in large letters at the base of the stele of Madonna in the harbor of Messina. From that year, the city of Messina celebrates Our Lay of the Letter on June 3, with a crowded procession of the silver "fercolo" of Our Lady and on August 15, with the procession of the colossal "Vara", dragged by hundreds of faithful dressed in white, with the participation of hundreds of thousands of faithful and curious people from all over Europe. In Messina, on June 3, will be celebrated the religious feast. In the morning, takes place a solemn celebration presided by archbishop with the participation of all religious and chivalric orders. In the afternoon, the simulacrum representing the Madonna of the letter, is carried in procession, work of the master Lio Gangeri dating from the nineteenth century. The moat solemn feast is that of the Assumption which takes place on August 13 to 15, attended by thousands of faithful and tourists. On August 14, two huge statues of wood and cardboard march in the streets of Messina, representing respectively "U Giganti" and "A Gigantissa" (The Giants). On August 15, is celebrated the feast of the Assumption. During the day, a "vara" representing the Assumption into heaven of the Virgin Mary, dating back to 1535, is carried in procession. This Construction is nothing more than a complex gimmick composed of many gears and leaning on a strain of very sturdy oak. All devotees actively participate to the procession clapping and shouting "Long live to Maria". As soon as the Vara comes to the cathedral, it takes place a magnificent show of fireworks that are fired from small boats near the statue of Madonna in the harbor of Messina. Some parts of this article are from Wikipedia

In 1624, a horrible plague haunted Palermo, and during this hardship St 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 St Rosalia would be venerated as the patron saint of Palermo, and a sanctuary was built in the cave where her remains were discovered.

In 1625 the relics were placed inside a casket made of silver and glass, kept inside the Archbishop's Palace, and the same year were brought in procession to commemorate the miracle, inaugurating a tradition that in more than three centuries has undergone very few interruptions.

The celebration, called the festino, is still held each year on July 15. It is still a major social and religious event in Palermo.

The feast attracts hundreds of thousands of faithful and curious tourists, and consists in performances, exhibitions and concerts, starting with the first days of July and culminating in the religious celebrations of July 15. Each year a different theme is developed, while keeping the basic story of the miracle of the victory over the plague. On the night of July 14 the feast reached the peak, with a solemn procession from the Palace of the Normans to the sea according to an ideal route from the dead (the plague) to life (the light of fireworks on the beach).
The procession is composed of a triumphal chariot with the statue of the saint, pulled by oxen; it stops in front of the cathedral, at the four corners (wher, traditionally, the mayor lays flowers to the the foot of the statue of Santa shouting "Long live to Palermo and Saint Rosalia!" and at the harbor, where itakes place a great show of fireworks accompanied by symphonic music live performed.

Since the late nineties, the show has become a theatrical performance in all intents and purposes, with light effects and spectacular acrobatic dances, representing the last days of the plague in Palermo.

The show has itinerant character, in fact, after the city performance, it is represented in various parts of the world, in order to recover part of the costs incurred for the entire feast.

Source Wikipedia