Four companies or half of such a regiment were called either a squadron or by the Italian name _battaglia_, to which must be traced our modern word battalion. Two such regiments were called a brigade, which marks the latest advance in organisation made by Gustavus. Maurice of Nassau had been before him in the formation of brigades but had not reduced them to uniform strength. The Swedish brigades had a stereotyped formation for battle, and were called after the colour of their standards, the white, the blue, the yellow, and finally the green, better known as the Scots Brigade, which is that wherein we are chiefly interested.
Passing next to the cavalry, the marks of Gustavus's reforming hand are not less evident. The force at large was divided into cuirassiers and dragoons. Of these the latter, who were armed with muskets and were simply mounted infantry, may be dismissed without further observation. The cuirassiers, except outwardly, bore a strong resemblance to the Reiters, for, though stripped of all defensive armour except cuirass and helmet, they still carried two pistols as well as the sword. Gustavus, however, here as with the infantry, took a line of his own. He began by reducing the depth of the ranks from the bottomless profundity of the Reiters to three or at most four; and though he still opened his attack with the pistol and so far adhered to missile tactics he to a considerable extent combined with them the action by shock. As in the infantry, it was Pescayra's system that he wished to supersede. The Reiters, as we know by the testimony of many eye-witnesses, were often so anxious to go to the rear and reload that they fired their pistols at absurd ranges, sometimes indeed hardly waiting to fire before they turned about. Unable to apply to cavalry the system which he had adopted for the infantry, and failing in common with all his contemporaries to grasp the principle that, since a horse has four legs and a man two, the evolutions of horse and foot must be fundamentally different, Gustavus none the less determined that his cuirassiers should at all events come to close quarters with their enemy. He therefore trained them not to fire till they could see the white of their opponents' eyes, and having fired to strike in with the sword.