From the earth to heaven
The initial project for the layout of the square, which began in 1608, was designed with
great monumentality by the Florentine architect Giulio Lasso. The architectural portion of the four corners was completed in 1620, under the direction of Mario Smiriglio, from Palermo, the engineer of the Senate and former site supervisor when Lasso was directing the works. At around that time, the designs for the decorations were also prepared, with the collaboration of Nicasio Azzarello and Giovanni D’Avanzato.
The iconological plan of the work, devised by the scholar Filippo Paruta, is based on the arrangement of three distinct orders, symbolising the deep interpenetration of the human and divine dimensions: the Tuscan order at the bottom; the ionic order in the middle; and the composite order at the top. The interpenetration of the earthly and divine elements can also be seen on the numerical level, where the number four refers to the earthly sphere (the seasons, the elements and the ages), whereas three is the sacred number par excellence.