Artillery was another important, but expensive, element in the Renaissance prince's army. Smaller and more mobile cannons were made for use in pitched battles as well as sieges. There was no standardization in the Renaissance artillery corps, each cannon being made by an independent contractor. The French, with Europe's best artillery, had 17 separate gauges of artillery requiring 17 different sizes of shot. The Hapsburg emperor, Charles V, had 50 different gauges. Obviously, this could create untold confusion in the heat of battle.
The advent of artillery made the tall thin walls of medieval castles obsolete, since they were so easily breached by cannons' firepower. However, this did not make fortifications obsolete. By the early 1500's, a new style of fortifications, the trace Italienne, was coming into use and slowing down, if not stopping artillery. These new fortifications were much thicker and more elaborate than their medieval predecessors, having multiple sets of walls, moats, and bastions set at different angles to one another to provide flanking fire from various directions against any enemy assaults. As with muskets and artillery, these new forts were so expensive that only kings could afford them or, more properly, afford to go into debt to bankers to buy them. And, by the same token, this increased the kings' power and put any rebellious nobles more at the kings' mercy.
This new type of warfare and army showed the beginnings of some aspects we associate with modern warfare. For one thing, it was expensive because of the size of its armies and the new technology. It was also very destructive to the inhabitants who were unlucky enough to be in the path of these plundering mercenaries and their hordes of camp followers. The seventeenth century general, Albrecht von Wallenstein, once said he could better support an army of 50,00 than one of 20,000 since it could more effectively plunder the countryside. This says a lot about supplying such armies and its effect on military strategy: fight in the enemy's territory and make him pay for the war. Finally, the new warfare was much bloodier than the medieval warfare that preceded it. We find nobles complaining because any low born peasant with a small amount of training and a gun could blow them out of the saddle. Even more significantly, the humanists condemned warfare for its bloodiness, no matter to what class. Throughout the modern era, that outcry has slowly gained force with the growing destructiveness of warfare.
The Church was still the largest single landholder in Western Europe, making it mandatory for kings to control this vital source of revenue and propaganda. Luckily for the kings, the Church's power and prestige were seriously weakened by the popular discontent and corruption that climaxed with the Great Schism. In France, kings had gained the loyalty of the local clergy against the Italian higher clergy appointed by the popes and won their struggle to rule the French clergy in the Pragmatic Sanction of Bourges in 1438. This recognized the king's claim to the Gallican Liberties, transferring the direct loyalty of the French clergy from the pope to their king.