Florentine sculptor and architect. Trained with Baccio Bandinelli (1493-1560) and Jacopo Sansovino (1486-1570). In 1550, went to Rome, where he worked with Giorgio Vasari (1511-1574) on the construction of the Villa Giulia, which features a spectacular three-level nymphaeum overlooking and terminating the main courtyard. In 1555, returned to Florence to finish the vestibule of the Biblioteca Laurenziana as planned by Michelangelo (1475-1564). For Cosimo I de' Medici (1519-1574), Ammannati began the expansion of the Palazzo Pitti, designing the monumental three-level courtyard with its distinctive large ashlars. Ammannati also designed the Santa Trinita bridge - rebuilt after the 1944 bombings - and the Fountain of Neptune at the corner of the Palazzo Vecchio in Piazza della Signoria. After making contact with the Jesuits, for whom he designed the church of San Giovannino, Ammannati gradually abandoned mannerist intellectualist themes in favor of a stricter, more moralistic interpretation of art. Three sections of his notes for an architectural treatise survive: a volume of drawings known under the title of Cittą ideale (Department of Prints and Drawings of the Uffizi, 3382A-3464A), and two notebooks with studies on practical geometry and fortifications (Biblioteca Riccardiana, Ms. Ricc., Edizioni Rare 120). The Riccardiana notebooks also include the manuscript on the use of military compass (inv. 1277), held by the Museo Galileo of Florence.