This division into separate Armies, each forming a definite Unit, with its own Commander and Staff, and numbered from right to left, was first seen in the two great wars carried on by Prussia in 1866 and 1870. Each Army had its own Lines of Communication, and moved and fought independently under its Commander, in obedience to general instructions issued at intervals by Moltke, as Chief of the General Staff, on the authority of the Commander-in-Chief, the King of Prussia. This system was followed in Manchuria by the Japanese, who had four, and later five, Armies in the field under one Supreme Command. It is now obligatory on all nations putting several hundred thousand men in the field to organize them in separate Armies. In any future war between France and Germany each Power will probably form five such Armies under one Supreme Commander, or “Generalissimo,” as the French (following Jomini) style him. Each Army will have its own sphere of action and Lines of Communication. The modern organization by Armies differs from that adopted by Napoleon for the invasion of Russia, and in the German campaign which followed in 1813. It is true that, by forming large detachments to the flanks, he divided his enormous forces into what were practically separate Armies; but the main body in the centre was not only by far the most important, but was under Napoleon’s own command. In fact he commanded one of the Armies himself, while at the same time directing the whole Force. It is now recognized that this arrangement was far from successful, even under Napoleon, and would be impossible for a lesser man. The Supreme Commander must not himself command one of his Armies. If he were to attempt this, the other Armies would become merely large detachments; plans would tend to be based on the movements of the main body; and the operations of the Armies would lose in scope and independence. The size of Armies must obviously be limited to the number which one man can command. This, according to Clausewitz, should not exceed 120,000 to 150,000. The total strength depends mainly on the number of Subordinate Commands. Napoleon was of opinion that five were enough for one man to command. Clausewitz laid down eight as the maximum. In the great hosts of modern nations _Armies_ are not organized in peace, and their composition in war is kept secret, but it is certain that they will not consist of less than three, or of more than six _Army Corps_ (or _Divisions_, where Army Corps are not used), and most probably of four or five, with two or three _Cavalry Divisions_. We have thus traced the development of the _Higher Commands_, or those of all Arms, from the _Division_ to the _Army_, and will now consider the Administrative Services and Staff allotted to them. THE ADMINISTRATIVE SERVICES