The great political writers of Florence differed in opinion with regard to the new constitution. Donato Giannotti censured it, declaring it to be "a cause of sedition, instead of a bond of peace and concord, because the founders of that government directed it entirely against the nobles, its former rulers in the days of Frederic, and who now being in constant fear of attack, were obliged to fly to arms on every occasion."[249] Machiavelli, on the contrary, praised the Constitution, and wound up by saying: "With these military and civil institutions the foundations of Florentine freedom were laid. Nor is it possible to imagine how much authority and strength Florence thereby gained in a short space. For she not only became the head of Tuscany, but was counted among the foremost of Italian cities, and might have risen to any height had she not been afflicted by new and frequent divisions."[250] Machiavelli judged rightly. Both contemporary chroniclers of these events and the impartial voice of history fully confirm the truth of his words. The city now began to be enriched by new public monuments. The Communal palace, otherwise known as the palace of the Podestà, rose from the ground, and the Santa Trinità bridge was built, chiefly at the expense of a private citizen. The gold florin was now issued, and, being mixed with the best alloy, speedily obtained currency[251] not only in all European markets, but even in the Levant, greatly to the advantage of Florentine commerce, which was daily becoming more widely extended. The nobles were discontented, of course, and hastened to show their ill-feeling, in 1251, by their almost unanimous refusal to join in the war against Pistoia. But when a few of them were sent into banishment the others soon quieted down. The Guelph exiles were recalled, adversaries within the city made peace, and now, that Frederic II. was dead, the aristocracy was kept in check by the strength and self-confidence of the popular party. Shortly afterwards external wars began, and these were carried on with so much success that the following ten years were known as the years of victory. V.