The first architectural treatise written in Italian rather than Latin: twenty-five books cast as a dialogue in which the architect explains to a prince how to build a whole new city, Sforzinda, laid out as an eight-pointed star.
Filarete (“lover of virtue”) was a Florentine sculptor who had cast the bronze doors of Old St Peter’s in Rome before entering the service of Francesco Sforza, Duke of Milan, for whom he designed the great hospital, the Ospedale Maggiore (begun 1456). His treatise circulated in manuscript; it was not printed until the nineteenth century, but copies were made for the Sforza and the Medici and it was widely known.
The book is half manual and half romance. The architect and his patron talk through the choice of a site, the foundation ceremony, the plan of the city and the design of each of its buildings (cathedral, palace, hospital, prison, houses for every class), and in the middle of the work the builders dig up an ancient “Golden Book” describing a lost city of the past, which becomes a second, harbour city. Filarete is scornful of the “modern” (Gothic) manner and insists on the ancient one, which he associates with Brunelleschi.
Its lasting contribution is the image of the planned, geometrical city: Sforzinda is a star formed by two squares turned 45° to one another inside a circular moat, with gates in the re-entrant angles, towers at the points and sixteen streets running from the central square to the walls. It is the ancestor of the star-shaped fortress towns of the next two centuries.
The book, part by part
I Books I–V: The architect and the founding of the city
The origin of building (Adam sheltering his head with his hands), the proportions of the body and the orders, the architect as the mother who carries the design, the patron as its father. The choice of a healthy valley and the laying out of Sforzinda.
Rules: The city as a star · Radial streets from a central square
II Books VI–XIII: The buildings of the city
The cathedral, the prince’s palace, the piazze and markets on the radial streets, houses for gentlemen, merchants and artisans, the hospital modelled on Filarete’s own Ospedale Maggiore in Milan, and a ten-storey tower of Virtue and Vice.
III Books XIV–XXI: The Golden Book and the port city
An ancient book found in the foundations describes the city of a legendary king; Filarete reconstructs its temples, palaces and harbour, giving free rein to his taste for fantastic, many-storeyed designs.
IV Books XXII–XXV: Drawing and the arts
Instructions on drawing, perspective, colour and materials, and a dedication to Piero de’ Medici in the version sent to Florence.