This event celebrates the miracle of the liberation of Palermo from the plague in 1624, after the relics of Santa Rosalia (called "La Santuzza") were found on Mount Pellegrino, defined by Goethe "the most beautiful promontory in the world".

According to tradition, the Saint appeared in a dream to a hunter and told him where her bones were kept. The bones were found on 15th July 1624 while the city was plagued by a very serious pestilence and they were carried in procession. After that, the calamity ended.  Since that moment on, Santa Rosalia (born and lived in Palermo between 1130 and 1170), has become the Patroness  of the city, taking the place of Santa Cristina and, from 1625, the first feast in her honor was organized at the behest of cardinal Giannettino Doria. 

The celebrations in honor of the Saint have undergone changes over the centuries, although the charm of tradition has been kept unchanged. The Saint belonged to the rich and noble Sinibaldi family and she also lived at the court of Roger II, before retiring as a hermit in a cave of Mount Pellegrino, where she died. 

The Feast, which every year attracts thousands of tourists, begins on 10th July and  lasts for five days. It reaches its peak in the night between 14th and 15th July, when a crowd of people coming from Palermo accompanies the traditional parade of the Triumphal Chariot, along the ancient road axis  Cassaro up to the coast, where the famous fireworks display takes place on the Gulf of Palermo. The Chariot - ten meters high and nine meters in length - hosts musical bands and people in historical costume. It seems to be a big ship, with a statue of Santa Rosalia placed at the stern, and it has been replaced several times in search of more and more solemn scenographic effects (the first chariot dates back to 1686).

The Feast ends on 15th with the Pontifical Mass in the Cathedral and the solemn procession of the relics of St. Rosalie kept in a silver urn. All the Confraternities of Palermo open the procession, followed by religious orders and the Clergy. After having crossed the ancient Cassaro, the procession arrives at Piazza Marina Cardinale to hear the Cardinal's words addressed to the city. Then, the procession continues across the old historical center until the relics return to the Cathedral, among the shouts of the devotees who glorify the darling Saint. 

St. Rosalie and her feast contribute to strengthen the collective sense of identity of Palermintans, which finds expression in the choral cry “Viva Palermo and Santa Rosalia”, song during the procession. Numerous shows and cultural events take place in the city's squares and historic buildings, while some districts are decorated with spectacular lights.

The Saint hermit is also celebrated on 4th September at the Sanctuary on Mount Pellegrino where she died in a cave in 1170.  Become a destination for pilgrimages, the sanctuary is full of votive offerings donated by the devotees and under a Baroque canopy there is a statue representing the Saint, a work by the Florentine Gregorio Tedeschi of 1630. In 1737 King Charles III of Bourbon gave the Saint the sumptuous golden garment that covers her in this simulacrum, in front of which in 1787 Johann Wolfgang von Goethe wrote: "The head and the hands, of white marble, were [...] however so natural, so seductive, to make believe that she breathed and moved".