The paper deals with the activity of two generations of the architects of the Florentine Sangallo family in the field of fortification: Giuliano da Sangallo, Antonio da Sangallo the Elder and Antonio da Sangallo the Younger. Due to their projects the fortifications of bastioned type spread widely not only on the Italian territory but also to the North from the Alpes. The author analyzes  the fortresses of Nettuno, Civitavecchia, Cività Castellana, the fortification of Borgo Vaticano in Rome, the ideas of Antonio da Sangallo the Younger for Parma and Piacenza fortification and others.

1. Vasari G. Zhizneopisanija naibolee znamenityh zhivopiscev, vajatelej i zodchih [Lives of the most famous painters, sculptors and architects]. Moscow, vol. III, 1959, 548 p.
2. Revzina Yu. E. Arhitektura, vojna i geografija: fortifikacija XVI-XVIII vekov v Evrope i Rossii [Architecture, war and geography: the fortification of the XVI-XVIII centuries in Europe and Russia]. Moscow, 2016, 343 p.
3. Ackerman J. S. The Architecture of Michelangelo. Chicago, 1986, 296 p.
4. Antonio da Sangallo il Giovane. La vita e l’opera. A cura di G.Spagnesi. Roma, 1986, 355 p.
5. De la Croix H. Military Architecture and the Radial City Plan in Sixteenth Century Italy. The Art Bulletin, - XLII, 1960, pp. 263-290.
6. De la Croix H. Military Considerations in City Planning: Fortifications. New York, George Braziller, 1972, 217 p.
7. Fara A. La città da guerra nell’Europa moderna. Torino, Einaudi Editore, 1993, 222 p.
8. Hale J. R. Renaissance Fortification. Art or Engineering. London, Thames and Hudson, 1977, 64 p.
9. Promis C. Dell'arte dell'ingegnere e dell'artigliere dalle origini sino al principio del XVI secolo. Torino, Ed. Chizio e Mina, 1841, 435 p.