The relative numbers of particular branches of the service were changed during the war. In the beginning the proportion of the cavalry to the infantry was as one to five, but soon they became one to three, and in the latter period they were sometimes the strongest. This striking fact is a proof both of the deterioration of the troops and of the art of war. In the exhausted country, the army could only be maintained by a strong force of cavalry, who could forage further and change their ground with more rapidity. As all who hoped for independence or booty pressed into the cavalry it was in better condition proportionately than the infantry, who at last were reduced to support themselves by reaping the scanty remains left by the horsemen. Undoubtedly the cavalry also became worse, the want of good horses was at last more sensibly felt than that of men, and the heavy cavalry could not be kept up, whilst in the last year the service of the scouts and foraging parties for the commissariat was brought to great perfection. Nevertheless the cavalry were the most effective, for it was their task to decide the battle by their charge. The last army with skilled infantry and Dutch discipline was that of Bavaria under Mercy, from 1643 to 1645. The tactics of armies had slowly altered in the course of the century. The old Landsknecht army advanced to battle in three great squares,--the advanced guard, the main body, and the rear guard--disregarding roads and corn-fields; before it went pioneers, who filled in ditches and cut down hedges to clear the way for the bulky mass. For battle, the deep square masses of infantry placed themselves side by side, each square mass consisted of many companies, sometimes of many regiments; the cavalry formed in a similar deep position at the wings. There was no regular reserve, only sometimes one of the three masses was kept back for the final decision; a select body of men, the forlorn hope, was formed for dangerous service, such as forcing the passage of a river, covering an important point, or turning the enemy's flank. Since fire-arms had prevailed over pikes, these great battalions were surrounded by files of sharpshooters, and at last special bodies of sharpshooters were formed and attached to them. In the war in the Netherlands, the unwieldiness of these heavy squares led to breaking the order of battle into smaller tactical bodies. But it was only slowly, that formation in line and a system of reserve were organized. Much of the old method continued in the Imperial army in the beginning of the war. Still the companies of infantry were united in deep squares--in battalions. To take firm positions and assume defensive warfare had become too much the custom in inglorious campaigns against the wild storming Turks. The weight and tenacity of deep masses might certainly be effective, but if the enemy succeeded in bringing his guns to bear upon them, they suffered fearfully, and were very unwieldy in all their movements.