The Malplaquet proclamation was issued by Arthur Wellesley, 1st Duke of Wellington, commander of the Anglo-allied army on 22 June 1815. It announced to the French people that Wellington's army was there to restore their rightful king (Louis XVIII) and government that had been usurped by Napoleon Bonaparte on his return from the island of Elba; and that their lives and their property rights would be honoured.
Prelude
In response to Napoleon Bonaparte leaving Elba and landing in France on 13 March 1815 Seventh Coalition powers meeting at the Congress of Vienna declared Napoleon Bonaparte an outlaw and that they would render "all the assistance requisite to restore public tranquillity" to the French King and nation.
After the Seventh Coalition's victory at the Battle of Waterloo on 18 June 1815, the Anglo-allied army under the command of Wellington and a Prussian army under the command of Prince Blücher followed up the general French retreat and crossed the frontier into France intending to march on Paris. Although they marched close enough to come to each other's aid if needed the commanders chose slightly different axes of advance.
At daybreak of 19 June, that portion of Wellington's army which had fought the Battle of Waterloo, broke up from its bivouac, and began to move along the high road to Nivelles. Those troops which had been posted in front of Hal during 18 June, were likewise directed to march upon Nivelles. Wellington's army occupied Nivelles and the surrounding villages during the night of 19 June; in the course of which the Duke arrived from Brussels, and established his headquarters in the town. It was there that he issued a general order to his army. In the general order he made it clear to those under his command:
The Anglo-Allied Army marched on 20 June to Binche and Mons with the cavalry screen fanning out to cover the van and flanks of the army. Wellington established his headquarters at Binche. On 21 June, Wellington crossed the French frontier, moving the principal portion of his army to Bavay, and the remainder from Mons upon Valenciennes, which fortress was immediately blockaded; and established his headquarters at Malplaquet, on site of the Battle of Malplaquet where the Duke of Marlborough and Prince Eugene of Savoy had won a famous victory against the French a century before.
Proclamation
At Malplaquet Wellington issued a proclamation to the French people that Napoleon Bonaparte was an usurper and that his army came as liberators not as enemy invaders and that he had issued orders to his army that all French citizens who did not oppose his army would be treated fairly and with respect.
In contrast, no proclamation of a similar nature was issued by Prince Blücher, commander of the Prussian army, nor were any direct orders given by the latter to remind his troops that France was "to be treated as a friendly country", or to forbid them taking anything "for which payment be not made".
In the opinion of Siborne and Gifford:
Meanwhile, the British, Dutch, and German troops under the Duke of Wellington acquired from the outset the goodwill and kindly disposition of the inhabitants of the country through which they passed. The Anglo-Allied troops inspired the people with confidence: the Prussians awed them into subjection.
Much of the cause of all this may be traced to the different views entertained by the two great Commanders. Blücher's extreme hatred of the French would not allow him to modify, still less to abandon, the opinion which he had imbibed from the first moment he heard of the escape of Napoleon from Elba; that they ought not only to be thoroughly humbled, but also severely punished. Neither he nor his soldiers could ever forget the cruelties and extortions which their own country had been compelled to endure when overrun by the French: and now that they were once more brought into the land of their enemies, and another period of retribution had arrived; but one sentiment pervaded the whole Prussian Army — that those who had not scrupled to inflict the scourge of war throughout the whole continent, should, in their turn, be made duly sensible of its evils. In Siborne's opinion a contrary train of ideas, or a different course of proceeding, on the part of the Prussians was scarcely to be expected. Hence the value of the excellent and orderly conduct of the British troops operating as a salutary counterpoise to the domineering and revengeful spirit which actuated the Prussians.