possible from two factors in the situation before him.

The first factor was that the allied army, seeing its great numbers, the comparatively small accumulation of supplies which it could yet command, the great length of frontier which it had to watch, was spread out in a great number of cantonments, the whole stretch of which was no less than one hundred miles in length, from Liège upon the east or left to Tournay upon the west or right.

The second factor which gave Napoleon his chance was that this long line depended for its supply, its orders, its line of retreat upon two separate and opposite bases.

The left or eastern half, formed mainly of Prussian subjects, and acting under Blucher, had arrived from the east, looked for safety in case of defeat to a retreat towards the Rhine, obtained its supplies from that direction, and in general was fed from the east along those communications, continual activity along which are as necessary to the life of an army as the uninterrupted working of the air-tube is necessary to the life of a diver.

The western or right-hand part of the line, Dutch, German, Belgian, and British, acting under Wellington, depended, upon the contrary, upon the North Sea, and upon communication across that sea with England. That is, it drew its supplies and the necessaries of its existence from the west, the opposite and contrary direction from that to which the Prussian half of the Allies were looking for theirs. The effect of this upon the campaign is at once simple to perceive and of capital importance in Napoleon’s plan.

Wellington and Blucher did not, under the circumstances, oppose to Napoleon a single body drawing its life from one stream of communications. They did not in combination command a force defending one goal; they commanded two forces defending two goals. The thorough defeat of one would throw it back away from the other if the attack were delivered at the point where the two just joined hands; and the English[1] or western half under Wellington was bound to movements actually contrary to the Prussian or eastern half under Blucher in case either were defeated before the other could come to its aid.

Napoleon, then, in his rapid advance upon Belgium, was a man conducting a column against a line. He was conducting that column against one special point, the point of junction between two disparate halves of an opposing line. He advanced therefore upon a narrow front perpendicular to, and aimed at the centre of, the long scattered cordon of his double enemy, which cordon it was his business if possible to divide just where the western end of one half touched the eastern end of the other. He designed to fight in detail the first portion he could engage, then to turn upon the other, and thus to defeat both singly and in turn.

I will put this strategical position before the reader in the shape of an English parallel in order to make it the plainer, and I will then, by the aid of sketch maps, show how the Allies actually lay upon the Belgian frontier at the moment when Napoleon delivered his attack upon it.

Imagine near a quarter million of men spread out in a line of separate cantonments from Windsor at one extremity to Bristol at the other; and suppose that the eastern half of this line from Windsor to as far west as Wallingford is depending for its supplies and its communications upon the river Thames and its road system, and is prepared in case of defeat to fall back, down the valley of that stream towards London.

On the other hand, imagine that the western half from Swindon to Bristol is receiving its supplies from the Severn and the Bristol Channel, and must in case of defeat fall back westward upon that line.

Now, suppose an invading column rather more than 120,000 strong to be advancing from the south against this line, but prepared to strike up from almost any point on the Channel. It strikes, as a fact, from Southampton, and marches rapidly north by Winchester and Newbury. By the time it has reached Newbury, the eastern half of the opposing line, that between Wallingford and Windsor, has concentrated to meet it, but is defeated in the neighbourhood of that town.

Such a battle at Newbury would correspond to the battle at Ligny (let it be fought upon a Friday). Meanwhile, the western half, hurrying up in aid, has failed to effect a junction before the eastern half was defeated, comes up too late above Newbury, and finding it is too late, retires upon Abingdon. The victorious invader pursues them, and at noon on the second day engages them in a long line which they hold in front of Abingdon.

If he has only to deal in front of Abingdon with this second or western half, which hurried up too late to help the defeated eastern half, he has very fair chances of success. He is slightly superior numerically; he has, upon the whole, better troops and he has more guns. But the eastern half of the defending army, which has been beaten at Newbury, though beaten, was neither destroyed nor dispersed, nor thrust very far back from the line of operations. It has retreated to Wallingford, that is towards the north, parallel to the retreat of the western half; and a few hours after this western half is engaged in battle with the invader in front of Abingdon, the eastern half appears upon that invader’s right flank, joins forces with the line of the defenders at Abingdon, and thus brings not only a crushing superiority of numbers upon the field against the invader, but also brings it up in such a manner that he is compelled to fight upon two fronts at once. He is, of course, destroyed by such a combination, and his army routed and dispersed. An action of this sort fought at Abingdon would correspond to the action which was fought upon the field of Waterloo, supposing, of course, for the purpose of this rough parallel, an open countryside without the obstacle of the river.

The actual positions of the two combined commands, the command of Blucher and the command of Wellington, which between them held the long line between Tournay and Liège, will be grasped from the sketch map upon the next page.

The reader who would grasp the campaign in the short compass of such an essay as this had best consider the numbers and the positions in a form not too detailed, and busy himself with a picture which, though accurate, shall be general.

Let him, then, consider the whole line between Liège and Tournay to consist of the two halves already presented: a western half, which we will call the Duke of Wellington’s, and an eastern half, which we will call Blucher’s: of these two the Duke of Wellington was Commander-in-chief.

Larger Image

Next, note the numbers of each and their disposition. The mixed force under the Duke of Wellington was somewhat over 100,000 men, with just over 200 guns.[2] They consisted in two corps and a reserve. The first corps was under the Prince of Orange, and was mainly composed of men from the Netherlands. Its