In order to understand how it came about that the British infantry within a few years proved more than a match for the French in the Peninsular War, it is necessary to have some knowledge of the methods of fighting previously adopted by the armies of the two nations, and then to see how Moore altered these methods, by assimilating the good and by eliminating the bad, by pruning and by inducing fresh growth. We shall see that, in the new system of training, everything depended on the regimental officer; and we shall see that, when war came, it was the regimental officer who made the British army almost invincible. Without entering too deeply into the history of tactics, we may say that up to the middle of the eighteenth century the fighting formation of infantry, whether in attack or defence, consisted generally of solid bodies of troops, which marched up in two massive columns, and then deployed, in the face of the opposing force, into two lines each composed of three ranks. Skirmishers were then unknown; and very great attention was paid to drill. About 1757 we find the Austrians using light troops (Croats) to harass Frederick the Great's army on the march; but these do not appear to have been properly organised, and, though always annoying, they seldom acted with real judgment. In 1774 Mesnil Durand invented a system in which skirmishers played a considerable part. Battalions were to move in double company columns at deploying intervals, two of the ten companies of each battalion acting as skirmishers to cover the whole front of the line of columns. It was held that in this way the fire of the skirmishers would make itself felt to such an extent that it would only remain for the heavy columns behind to push in and crush the enemy by sheer weight. This was to a certain extent the system adopted by the French in 1793, and employed by the French generals in the Peninsular War, and by Napoleon until his final defeat at Waterloo, except that the columns of attack were deep and solid, and not merely single battalion columns or lines of battalion columns.