But this treaty, in spite of its apparent stability, led in a few years to a fiercer struggle; for in 1258 the Florentines complained that Siena had infringed its terms by giving refuge to the Ghibellines they had expelled, and on the refusal of the Sienese to yield to these just remonstrances both states made extensive preparations for war.
The Strozzi palace in Florence and the Palazzo del Magnifico at Siena have fine specimens of these - the former of wrought iron, the latter in cast bronze.
Starting with a visit to Piombino, on the coast opposite Elba, he went by way of Siena to Urbino, where he made drawings and began works; was thence hastily summoned by way of Pesaro and Rimini to Cesena; spent two months between there and Cesenatico, projecting and directing canal and harbour works, and planning the restoration of the palace of Frederic II.; thence hurriedly joined his master, momentarily besieged by enemies at Imola; followed him probably to Sinigaglia and Perugia, through the whirl of storms and surprises, vengeances and treasons, which marked his course that winter, and finally, by way of Chiusi and Acquapendente, as far as Orvieto and probably to Rome, where Caesar arrived on the 14th of February 1503.
Bernardino di Siena (1472) has a fine Renaissance facade by Nicolo Filotesio (commonly called Cola dell' Amatrice), and contains the monumental tomb of the saint, decorated with beautiful sculptures, and executed by Silvestro Ariscola in 1480.
But, although greatly strengthened, the Guelphs, who now may be called the democrats as opposed to the Ghibelline aristocrats, were by no means wholly victorious, and in 1251 they had to defend themselves against a league of Ghibelline cities (Siena, Pisa and Pistoia) assisted by Florentine Ghibellines; the Florentine Uberti, who had been driven into exile after their plot of 1258, took refuge in Siena and encouraged that city in its hostility to Florence.
First, the emperor's wrath was stirred by the influence of France in the counsels of the republic; then Cosimo, who was no less jealous of the French, conceived the design of annexing Siena to his own dominions.
Of these the most frequented in 1904-1905 were: Naples (4745), Turin (3451), Rome (2630), Bologna (1711), Pavia (1559), Padua (1364), Genoa (1276), and the least frequented, Cagliari (254), Siena (235) and Sassari (200).
The 16th century boasts the names of Bernardino Fungai, Guidoccio Cossarelli, Giacomo Pacchiarotto, Girolamo del Pacchia and especially Baldassare Peruzzi (1481-1537), who while especially celebrated for his frescoes and studies in perspective and chiaroscuro was also an architect of considerable attainments (see Rome); Giovanni Antonio Bazzi, otherwise known as 11 Sodoma (1477-1549), who, born at Vercelli in Piedmont, and trained at Milan in the school of Leonardo da Vinci, came to Siena in 1504 and there produced some of his finest works, while his influence on the art of the place was considerable; Domenico Beccafumi, otherwise known as Micharino (1486-1550), noted for the Michelangelesque daring of his designs; and Francesco Vanni.
A Florentine army assisted by Guelphs of other towns was cunningly induced to believe that Siena would surrender at the first summons; but it was met by a Sienese army reinforced by Florentine exiles, including Farinata degli Uberti and other Ghibellines, and by the cavalry of Manfred of Sicily, led by Count Giordano and the count of Arras, with the result that the Florentines were - totally routed at Montaperti on the 4th of September 1260.
Thereupon certain Sienese citizens in Rome, headed by Aeneas Piccolomini (a kinsman of Pius II.), entered into negotiations with the agents of the French king and, having with their help collected men and money, marched on Siena and forced their way in by the new gate (now Porta Romana) on 26th July 1552.