or fatality which permitted Erlon and his 20,000 to be as
useless upon the 16th of June as though they had been wiped out in some
defeat is what makes of the 16th of June the decisive day of the campaign.

It was Erlon's failure to be present _either_ with Ney _or_ with Grouchy,
either upon the left or upon the right, either at Quatre Bras or at Ligny,
while each of those two actions were in doubt, which made it possible for
Wellington's troops to stand undefeated in the west, for the Prussians to
retire--not intact, but still an army--from the east, and for both to
unite upon the day after the morrow, the Sunday, and destroy the French
army at Waterloo.

It is upon Erlon's blunder or misfortune that the whole issue turns, and
upon the Friday, the 16th of June, in the empty fields between Quatre-Bras
and Ligny, much more than upon the famous Sunday at Waterloo, that the
fate of Napoleon's army was decided.

In order to make this clear, let us first follow what happened in the
operations of Napoleon's right wing against the Prussians opposed to
it,--operations which bear in history the name of "the Battle of Ligny."

LIGNY

"_If they fight here they will be damnably mauled._"

(Wellington's words on seeing the defensive positions chosen by the
Prussians at Ligny.)

Napoleon imagined that when he had crossed the Sambre with the bulk of his
force, the suddenness of his attack (for, though retarded as we have seen,
and though leaving troops upon the wrong bank of the river, it was sudden)
would find the Prussian forces in the original positions wherein he knew
them to have lain before he marched. He did not think that they would yet
have had the time, still less the intention, to concentrate. Those
original positions the map upon p. 41 makes plain.

The 124,000 men and more, which lay under the supreme command of Blucher,
had been spread before the attack began along the whole extended line from
Liege to Charleroi, and had been disposed regularly from left to right in
four corps d'armee.

The first of these had its headquarters in Charleroi itself, its furthest
outpost was but five miles east of the town, its three brigades had
Charleroi for their centre; its reserve cavalry was at Sombreffe, its
reserve artillery at Gembloux. The Second Corps had its headquarters
twenty miles away east, at Namur, and occupied posts in the country as far
off as Hannut (thirty miles away from Charleroi).

The Thir