Throughout the greater part of the twelfth and thirteenth centuries, Siena--usually more or less allied with Pisa, Pistoia and the Conti Guidi--was engaged in a series of wars with Florence, an intermittent struggle alternating with hollow, insincere treaties of peace. This was due to the antagonistic ideals of Guelf and Ghibelline, to the growing commercial rivalry between the two republics, each especially striving to get into the hands of its own merchants and noble bankers all the increasingly lucrative affairs of the Roman Curia, and, perhaps, more immediately to the fact that each was striving to extend its contado at the expense of the other. Poggibonsi, Colle di Val d'Elsa, Montalcino and Montepulciano--in which right was probably with Siena and might with Florence--were perpetual sources of contention, and the Sienese suffered severe defeats time after time. "Do not forget through eternity those that deny thee, that withdraw themselves from the homage they owe thee, that plot against thee and that bring shame to thee." So runs the black book of the Commune, the _Memoriale delle Offese_, in which these things were recorded. "Be mindful of Montepulciano, that, though it be of thy contado, most proudly endeavours to withdraw itself therefrom."[2] Grosseto was the first place of importance that, in 1224, fell permanently into the hands of the Sienese, a town previously swayed by the Counts Aldobrandeschi of Santa Fiora, those most potent nobles of the Sienese contado whose pride and whose imperialistic tendencies are recorded by Dante. Within the city the factions raged furiously. The power of the nobles or _gentiluomini_ was waning, even in Ghibelline Siena. It was laid to their charge that the wars with Florence had taken so unfavourable a turn, that the Florentines were ravaging the contado, had hurled donkeys into Siena with their catapults, and on one occasion had even penetrated into the city itself. By what appears to have been a comparatively peaceful revolution in 1233, the people obtained an increased share in the government; a supreme magistracy of Twenty-four was created, elected annually by the General [Illustration: In Castel Vecchio, the oldest part of Siena]