powder and firearms produced a radical change in the condition of the Italian communes. For mounted troops required much training and great expenditure. It was not enough to maintain great arsenals, to create and train a new breed of horses, but every trooper had also to be kept in steady practice, devote his whole time to warfare, and keep two or three squires continuously drilled and employed. These squires carried all the armour and weapons and led the knight's charger, which was only used in battle. Only then, too, were knight and steed in full harness, otherwise both would have been exhausted in the hour of danger. Hence it was impossible for our republics to raise cavalry, seeing that citizens, earning their living by trade and commerce, could not forsake their daily work to acquire the art of war. Therefore, soldiering became a regular trade, and all choosing it for their career speedily began to put a price on their swords. Thus from the closing years of the thirteenth century we begin to find _soldiers_ of various nationalities--Catalans, Burgundians, Germans, and other foreign horse--in the ranks of republican armies, and the number of these mercenaries was continually on the increase. Gradually, also, tradesmen were obliged to recognise that they had become personally useless in the field. Accordingly, whenever the republics were threatened with attack, they no longer ventured to give battle without hiring some captain with a band of foreign horse. Italian valour rapidly lost its prestige, and "Companies of Adventure"--soon to be the cause of our direst calamities--began to be formed. Later on, it is true that when Alberico da Barbiano, Attendolo Sforza, Braccio da Montone, and others adopted the same career, they rivalled and even surpassed the foreign adventurers, who had now often to yield the palm to Italian courage. Soon, in fact, many came from afar to learn the new art of war under these Italian captains whose skill first reduced it to a science. Nevertheless, few citizens of free states were able to devote their whole life to war. It was the nobles, the exiles, the unemployed--knowing no other trade--and the subjects of petty tyrants who joined the "Companies of Adventure." And whether small bands or large, Italian or foreign, they invariably hastened the ruin of all our communes, and more especially of Florence. The continual wars in which this State was now engaged no longer served to foster the military spirit and energy of its people. Always compelled to rely on the help of foreign mercenaries, it soon lost all confidence in its own resources, the which therefore rapidly declined. A campaign simply implied some financial operation, or the levying of fresh taxes to furnish sufficient capital for the hire of one of the captains of adventure, who always closed with the highest bid. The money found, it was often enough to send it to the State's surest and most powerful