Based on geometry as much as local conditions, the design of bastioned fortresses became the province of specialists whose plans might be based on theory rather than topography. Italians devised wholly “rational” plans for fortresses and cities in which geometric figures, especially stars formed by lines of fire, determined the plan of glacis, wide moat, and ramparts. But the development of printing in Germany and soon throughout Europe meant that Italian theories and designs spread rapidly and relatively cheaply. The plans, beautiful as designs and drawings in themselves, were often too fanciful or expensive to be built. The sixteenth century was an age of wide-ranging and talented theorists. Men we usually think of as painters and sculptors also designed fortifications. Leonardo da Vinci (1452–1519) worked in Milan from 1482 to 1498 for the ruling Sforza family on military and engineering projects. Leonardo also designed guns, crossbows, armored vehicles, submarines, a parachute, and a flying machine and made plans for fortresses. From 1502 to 1504 Leonardo worked in Florence as a military adviser, then returned to Milan to advise on castles from 1508 to 1513. From 1517 until his death in 1519 he lived in France in the service of Francois I. Another Italian, Francesco de Giorgio (1439–1502) wrote a treatise on military engineering with improved fortress designs, published in 1480. From 1480 to 1486 he served the Duke of Urbino, designing the fortifications of Urbino. By 1494 de Giorgio was working for the king of Naples and Sicily designing the fortifications in Naples. Even Michelangelo (1475–1564) was the military adviser to the city of Florence in 1529, and in 1547 he designed the Vatican defenses. The leading architectural writers and theoreticians, like Leon Battista Alberti (1404–72), devised an ideal symmetrical plan for forts and cities. The Italians eventually settled on the five-point star as the ideal shape. The streets radiated out from a central command post or headquarters (or city center with market hall and church) with streets leading to gates or the bastions. Streets in concentric circles completed the internal division. The ideal plan did not allow for individual variations; consequently, it never developed successful cities, but it could be found in army installations. In the sixteenth and seventeenth centuries the Italian designs spread through Europe and the European colonies. The French architect and military engineer Sebastien Le Prestre de Vauban, who built major fortresses on the French borders for Louis XIV, became the most skillful designer of fortresses using the bastion system. The first forts in the Americas—Louisburg in Nova Scotia, Canada, or Fort Augustine in Florida—are simple “provincial” examples of the Vauban fort. Fort McHenry in Baltimore, where The Star Spangled Banner was written, is a characteristic example of the bastion scheme with its central plan, wide earthen ramparts, bastions, and casemates. The Pentagon repeats the Renaissance five-sided, pentagonal plan with a central court, radiating street-like halls and concentric corridors. The castle design recommended by Leonardo da Vinci and Alberti has become the American headquarters and symbol of military power.