guarantee against French aggression.
His relations with Prussia were indeed of the friendliest character, as
is shown by the fact that secret negotiations were at this very time
taking place for the cession to Prussia of his hereditary Nassau
principalities of Dillenburg, Siegen, Dietz and Hadamar in exchange for
the Duchy of Luxemburg.

The proceedings of the inharmonious Congress of Vienna were, however,
rudely interrupted by the sudden return of Napoleon from Elba. Weary of
waiting for a formal recognition of his position, William now (March 15,
1815) issued a proclamation in which he assumed the title of King of the
Netherlands and Duke of Luxemburg. No protest was made; and the _fait
accompli_ was duly accepted by the Powers (May 23). The first act of the
king was to call upon all his subjects, Dutch and Belgians alike, to
unite in opposing the common foe. This call to arms led to a
considerable force under the command of the hereditary prince being able
to join the small British army, which Wellington had hurriedly collected
for the defence of Brussels. The sudden invasion of Belgium by Napoleon
(June 14) took his adversaries by surprise, for the Anglo-Netherland
forces were distributed in different cantonments and were separated from
the Prussian army under Bluecher, which had entered Belgium from the
east. Napoleon in person attacked and defeated Bluecher at Ligny on June
16; and on the same day a French force under Ney was, after a desperate
encounter, held in check by the British and Dutch regiments, which had
been pushed forward to Quatre Bras. Bluecher retreated to Wavre and
Wellington to Waterloo on the following day. The issue of the battle of
Waterloo, which took place on June 18, is well known. The Belgian
contingent did not play a distinguished part at Waterloo, but it would
be unfair to place to their discredit any lack of steadiness that was
shown. These Belgian troops were all old soldiers of Napoleon, to whom
they were attached, and in whose invincibility they believed. The Prince
of Orange distinguished himself by great courage both at Quatre Bras and
Waterloo.

William, after his assumption of the regal title, at once proceeded to
regularise his position by carrying out that necessary modification of
the Dutch Fundamental Law to which he was pledged by the Eight Articles.
He accordingly summoned a Commission of twenty-four members, half Dutch
and half Belgian, Catholics and Protestants being equ