Urbanistic practice in trecento Florence, although it spawned no codified theory, was more conceptually developed than we usually imagine. Buildings were forcefully presented and tautly interwoven with their sites by means of inventive, empirical procedures. Intricate webs of geometry structured architectural scenes of Giottesque three-dimensionality. Order and meaning were bestowed on urbanistic scenes that might well have become disordered and unfocused through the slow evolution and redesign of architectural projects. A pre-eminent case in point was the Piazza della Signoria. Documentary, archaeological, and historical evidence suggests that as the Palazzo Vecchio rose in 1299-1315, it underwent fundamental design changes largely inspired by the growing piazza around it and that the piazza itself, as it grew to its final form through the trecento, was guided with surprising precision by the visual demands of the palace, the medieval obsession with geometric structure, and the urbanistic patterns of the city.

Florence Cathedral continues to yield surprises, and it is not always necessary to dig for them. A detail as small and seemingly insignificant as a keystone is here revealed as evidence of a trecento project for a set of minor lanterns. Ironically, but for good reasons, this scheme was abandoned by the very architects who in all likelihood actually crafted the keystone, Filippo Brunelleschi and Lorenzo Ghiberti. The detail is full of implications about Early Renaissance architectural practice, and it would be the first documented, completed architectural "work" involving Brunelleschi.