would remain unexplained. V. Therefore, even in the days of Countess Matilda, we find the mass of the citizens divided and arranged in groups. We see on the one side the ancient _scholae_ transformed into associations of arts and trades, containing the germ of future greater and lesser guilds; on the other, family associations and clans of the _grandi_ or leading citizens, embryos of future societies of the towers. All these associations already formed the practical government of the city, in which the principal offices were filled by _grandi_ of Matilda's choice. It is quite probable that the post of _preside_ was reserved, in accordance with mediæval usage, to a single family or clan, perhaps to that of the Uberti, who were, as we shall see, among the most powerful in the city, and boasting a Germanic descent. Nevertheless, there was then no hostility, no separation between the great folk or _grandi_ and the people, all being united by common bonds and interests. In fact, as we have said, there will be soon documentary evidence that some of the _grandi_ engaged in commerce were chiefs of guilds, and already beginning to fight, side by side with the people, against the outlying nobility. It is true that they owned lands and herds, but these were then the main source of that Florentine trade and commerce in defence of which the first wars were undertaken. The castles surrounding the city barred all outlets for commerce; armed men were always swooping down from them to attack and maltreat all pack trains issuing from the city to convey its products and merchandise to neighbouring towns. With continual wars on her hands, the Countess Matilda could seldom afford any help, and consequently the Florentines, although fighting in her name, were practically left to their own resources. It was this alliance of all classes of citizens, united by identity of interests and singleness of purpose against a common foe, that then constituted the strength of that Florentine people whose loyalty, purity, and valour were so fervently praised by Dante and the chroniclers. This was the moment when virtue laid the foundations of the Commune's future freedom and wealth.