Milanesi, the commentator of Vasari, asserts that Francesco was the son of a seller of fowls in Siena, because he found the name of a "Giorgio di Martino, pollajuolo," in the registers, but seeing that he was bred in the guild, it is much more likely that he was related to the Giorgio di Martino already eminent there. His family had certainly become citizens of Siena by that date. Maestro Francesco di Giorgio Martini holds a large share in the correspondence of the Sienese government and of the _Opera_ in the latter part of the fifteenth century. On December 26, 1486, we find him first entering the pay of the Sienese Commune as public architect. He has a salary of 800 florins, and is bound to fix his home at Siena. He was recalled from Urbino for the purpose, having orders to arrive within six months, but the Duke Guidobaldo was not at all willing for him to leave. On May 10, 1489, the Duke writes to say that the absence of his architect (_mio architector_) would be a serious injury to him. During the time Francesco remained in Umbria he seems to have done the Commune good political service by keeping them informed of the dangers that threatened Florence from the offensive alliance between Lorenzo de Medici and the Pope Innocent VIII., who designed to take Città di Castello for Francesco Cibo. This would have endangered the peace of Siena, so the architect warned them to be prepared. After this, Magister Francesco became the bone of contention among several princes and republics. The Duke of Milan wrote, on April 19, 1490, to the Signoria of Siena, begging them to send the "intellexerimus magistrum Franciscum Giorgium Urbinatem" (see how the place he last worked at is named as his residence!) to Milan to give his opinion on the mode of placing the cupola. The Commune gave the permission, and on June 27, 1490, we find Magistro Francisco di Georgi di Siena (here again at Milan he is styled of Siena), with Magistro Johantonio Amadeo (Omodeo) and Johanjacobo Dolzebono (Gian Giacomo Dolcebono), elected as a supreme council of three, and giving their advice on the erection of the cupola at Milan, with the exact plan and measurements which would harmonize with the building as it then stood. He did not remain to see the plans carried out, but was on his recall to Siena remunerated with one hundred florins by the Fabbrica (_Opera_) of Milan. On October 24 of the same year, Giovanni della Rovere, the Prefect of Rome, wrote to the Signoria of Siena praying for the service of their architect, and on November 4, 1490, Virginio Orsino, Duke of Bracciano, begged him to go and build a fortress at Campagnano. Next Alfonso, Duke of Calabria, wanted him at the Castle of Capua, where he went between February and May 1491, and in August of the same year the Anziani, Lords of Lucca, petitioned for him. And so he is called from end to end of Italy, and wherever he goes he is received with honour as a grand architect.[232]