The fortified city of Valletta, founded in 1566 by the Knights of Malta, is one of the few Renaissance ideal cities to be built. Planned from the beginning and constructed on virgin ground, it follows a rigid gridiron scheme designed by the Italian architect Francesco Laparelli da Cortona (1521-1570) that is an exemplar of Neoplatonic planning principles of the age of humanism and constitutes a model of modern urban design. Although the founding and development of the city has been well investigated historically, the formal essence of its urban design has not yet been examined satisfactorily from an architectural perspective. While the executed plan has been interpreted until now as an imperfect materialization of one of the four known preparatory drawings by Laparelli, in this article I suggest the possibility that the town built is a further evolutionary step in a fully traceable design process based on a coherent system of trigonometric proportions. In addition to the physical evidence of the city's current digital terrain model, the method of design proposed here is largely supported not only by sixteenth-century architectural theory (as advanced by Albrecht Dürer, Sebastiano Serlio, and Pietro Cataneo) but also historically by a group of new Florentine towns founded in the late Middle Ages that exhibit the same compositional principles.
