What is the name of the ornate pediment that was one of the first signs Sicily was forming its own style of decorative architecture?
This is not to say that Sicily was completely isolated from trends elsewhere in Europe. Architecture in the island's major cities was strongly influenced by the family of the sculptor Domenico Gagini, who arrived from Florence in 1463. This family of sculptors and painters decorated churches and buildings with ornate decorative and figurative sculpture. Less than a century after his family had begun to cautiously decorate the island's churches (1531–37), Antonio Gagini completed the proscenium-like arch of the "Capella della Madonna" in the "Santuario dell'Annunziata" at Trapani. This pedimented arch to the sanctuary has pilasters — not fluted, but decorated heavily with relief busts of the saints; and, most importantly in terms of architecture, the pediment is adorned by reclining saints supporting swags linked to the central shield that crowns the pediment. This ornate pediment, although still unbroken, was one of the first signs that Sicily was forming its own style of decorative architecture. Similar in style is the Chiesa del Gesù (Illustration 14), constructed between 1564 and 1633, which also shows early signs of the Sicilian Baroque.
Thus a particular brand of Baroque architecture had begun to evolve in Sicily long before the earthquake of 1693. While the majority of those buildings that can be clearly classified as Baroque in style date from around 1650, the scarcity of these isolated, surviving examples of Sicily's 17th-century architectural history makes it hard to fully and accurately evaluate the architecture immediately before the natural disaster: the earthquake destroyed not only most of the buildings, but also most of their documentation. Yet more information has been lost in subsequent earthquakes and severe bombing during World War II.
The earliest example of Baroque on the island is Giulio Lasso's Quattro Canti, an octagonal piazza, or circus, constructed around 1610 at the crossroads of the city's two principal streets.  Around this intersection are four open sides, being the streets, and four matching buildings with identical canted corners. The sides of the four buildings are curved, further heightening the Baroque design of the buildings lining the circus. These four great buildings dominating the circus are each enhanced by a fountain, reminiscent of those of Pope Sixtus V's "Quattro Fontane" in Rome. However, here in Palermo the Baroque theme continues up three storeys of the buildings, which are adorned with statues in recessed niches depicting the four seasons, the four Spanish kings of Sicily, and the four patronesses of Palermo: Saints Cristina, Ninfa, Olivia, and Agata.
Capella della Madonna