Looking back on the period in which the greater guilds rose to power, we shall see that they simultaneously held in their grasp the commerce, wealth, and government of the Florentine Republic. We shall also readily understand the enormous energy they must have displayed in order to use politics as a means for increasing the opulence that, in the existing conditions of Italy, had become the chief strength of our communes. The Florentine merchants, having long divined that the future would belong to them, were always the firmest supporters of the Guelph party against the Imperial Ghibellinism of the nobles and had vowed eternal hatred to the latter. We may now imagine Florence as a huge house of business, situated in the centre of Tuscany, and surrounded by others all competing with it in the race for success. International law and equity were unknown to the Middle Ages: hence when any State felt envious of its neighbour, the obvious course to adopt was to prohibit that neighbour from traversing its territory, and exact unbearably heavy dues from the rival it feared. Accordingly, the Republic of Florence, being the object of still fiercer jealousy on account of the continual increase of its commerce, and lacking room to breathe, as it were, without access to the sea, would have been speedily reduced to impotence had it not resisted its neighbours by force of arms. Hence, the necessity of defending its existence involved the State in an uninterrupted series of wars, invariably terminated by treaties of commerce, in which the unfailing subtlety of the Florentines always won the advantage. We have seen from the beginning how Florence combated the neighbouring barons in order to secure the progress of its dawning trade, and subsequently obtained a passage through the Mugello for its increased traffic with Romagna and Lombardy. Later on, we have seen it engaged in fiercer struggles, and, after many vicissitudes, subduing almost all the Ghibelline cities of Tuscany, as, for instance, Volterra, Sienna, and Arezzo. And when inquiring why Florence should have remained so obstinately Guelph, even in the face of Papal threats, and repeating the same question Farinata put to Dante-- "Dimmi, perchè quel popolo è si empio Incontro a' miei in ciascuna sua legge?"[364] the invariable reply has been that in addition to political motives of a more general nature, it must be kept in mind that the plutocracy now risen to power had first attained wealth by doing its chief business with Rome. Sienna, Arezzo, and Volterra being on the road and closer to Rome, were doomed to defeat in any competition with Florence.