remembered in history than the
crowning day of Waterloo, was, in every military sense, the decisive day
of the campaign.

We shall see that it was Napoleon's failure upon that Friday completely to
defeat, or rather to destroy, the Prussian force at Ligny--a failure
largely due to Wellington's neighbouring resistance at Quatre Bras--which
determined the Emperor's final defeat upon the Sunday at Waterloo.

III

THE DECISIVE DAY

FRIDAY THE 16TH OF JUNE

QUATRE BRAS AND LIGNY

We have seen what the 15th of June was in those four short days of which
Waterloo was to be the climax. That Thursday was filled with an advance,
rapid and unexpected, against the centre of the allied line, and therefore
against that weak point where the two halves of the allied line joined, to
wit, Charleroi and the country immediately to the north of that town and
bridge.

We have further seen that while the unexpectedness of the blow was almost
as thorough as Napoleon could have wished, the rapidity of its delivery,
though considerable, had been less than he had anticipated. He had got by
the evening of the day not much more than three-quarters of his forces
across the river Sambre, and this passage, which was mapped out for
completion before nightfall, straggled on through the whole morning of the
morrow,--a tardiness the effects of which we shall clearly see in the next
few pages.

Napoleon's intention, once the Sambre was crossed, was to divide his army
into two bodies: one, on the left, was to be entrusted to Ney; one, on the
right, to Grouchy. A reserve, which the Emperor would command in person,
was to consist in the main of the Imperial Guard.

The left-hand body, under Ney, was to go straight north up the great
Brussels road.

Napoleon rightly estimated that he had surprised the foe, though he
exaggerated the extent of that surprise. He thought it possible that this
body to the left, under Ney, might push on to Brussels itself, and in any
case could easily deal with the small and unprepared forces which it might
meet upon the way. Its function in any case, whether resistance proved
slight or formidable, was to hold the forces of Wellington back from
effecting a junction with Blucher and the Prussians.

Meanwhile, the right-hand body, under Grouchy, was to fall upon the
extremity of the Prussian line and overwhelm it.

[Illustration]

Such an action against the head of the long Prussian cordon could lead, as
th