Book excerpt: Dominion of the Eye: Urbanism, Art and Power in Early Modern Florence radically revises our ideas about the origins of rationally planned public space in the European city. Through a spatial and historical analysis of the major squares of Florence, all built in the Trecento, together with primary civic monuments, Marvin Trachtenberg shows that, contrary to current belief, Florentine planners engaged in a theoretically sophisticated mode of practice. In these squares, geometrically structured perspectival views of the principal monuments were established long before Alberti and other Renaissance theorists may have promoted such planning. Trachtenberg demonstrates that this urbanistic scenography, deeply informed by medieval optical science, was closely allied with perspectival developments in architecture, painting, and sculpture, forming a unified visual culture that was highly attentive to the eye of the spectator. An analysis of the critical role of the piazza in the Florentine sociopolitical field reveals how the art of the piazza was part of state practice as a work of art. Including more than 50 new drawings and 200 illustrations, Dominion of the Eye challenges many of the cardinal truisms in the art history of the Renaissance, offering a new model for understanding the art of Italy in the early modern era.