The situation of the Allied armies was not exactly that of the Austrians and Sardinians in Italy in 1796-97; there was the possibility of striking at their point of junction and of beating each army separately, but the short and excellent line of communication between the points of concentration of Wellington’s and Blucher’s armies, namely, the Quatre-Bras-Sombreffe road, afforded each army such easy and rapid means of effecting a junction, although, in fact, it was not actually used as a means of co-operation, that there was a “moral” influence in it which went a long way towards defeating Napoleon’s object. This may sound somewhat exaggerated; but what was it that made Ney uneasy for his own right flank on the 15th-16th, before he attacked? The report sent by Girard that Prussian columns were on that road. What was Napoleon’s fear during the battle of Ligny? That Wellington would send a force from Quatre-Bras to join Blucher’s right, along this road. What was the chief advantage in Wellington’s position at Quatre-Bras? This road again, which afforded a means of joining the Prussians at Ligny, had the occasion arisen. And in what way was this road of use to Blucher at Sombreffe? He could co-operate with Wellington if Napoleon had attacked _viâ_ Mons. Blucher had decided to fight at Ligny, even though he had little hope of the arrival of Bulow’s Corps in time to join the battle. For he believed that Napoleon’s forces were not superior to his own in numbers; he had selected the position previously, and had had it surveyed carefully; he hoped that he would be able to hold his own either until Bulow arrived, or until night put an end to the fight. In the event of the Fourth Corps reaching the field in time to take part, the extra weight in numbers would decide in Blucher’s favour, or else the Corps would attack Napoleon’s right flank at a time when his troops would be most fatigued. Or again, if night came on, sufficient time would have been gained for Bulow’s arrival to be made certain before daybreak next day, when a successful attack on the French might confidently be expected. In both cases, any pressure on Wellington would be relieved, so that the Anglo-Dutch Army might combine with Blucher to overwhelm the whole of Napoleon’s forces. Thus Blucher reasoned. To refuse a battle would have meant a retreat along his communications with the Rhine, and Blucher was most unwilling to abandon his chances of joining with Wellington. The battle itself will not be described; but d’Erlon’s wanderings towards the field and away from it again, and the influence of these aimless manœuvres on the struggle, may be discussed here.