The Prince of Hessen-Cassel soon overtook Orkney, from whom he learned that St. Ghislain was too strongly held to be carried by his small force. The Prince therefore at once pushed on. Rain was falling in torrents, and the roads were like rivers, but he continued his advance eastward, behind the woods that line the Haine, almost without a halt, till at Aug. 26./Sept. 6. length at two o’clock on the morning of the 6th of September he wheeled to the right and crossed the river at Obourg three miles to the north-east of Mons. Before him lay the river Trouille curving round to the south by Mons, and in rear of it a line of entrenchments, thrown up during the last war, from Mons to the Sambre, to cover the province of Hainault. A short survey showed him that the lines were weakly guarded; and before noon he had passed them without opposition. His force, notwithstanding the weather and the state of the roads, had traversed the fifty miles to Obourg in fifty-six hours.
Too late Villars discovered that for the second time he had been duped, and that Marlborough had no intention of forcing his way into France through the lines of La Bassée and the wet swampy country beyond them, when he could pass the lines of the Trouille without loss of a man. He was in a difficult position, for Mons was slenderly garrisoned and difficult of access, though, if captured, it would be a valuable acquisition to the Allies. The approach to it from the westward was practically shut off by a kind of natural barrier of forest, running, roughly speaking, from St. Ghislain on the Haine to the north to Maubeuge on the Sambre to the south. In this barrier there were but two openings, the Trouée de Boussut between the village of that name and the Haine, and the Trouées d’Aulnois and de Louvière, which are practically the same, some miles further to the south. These will be more readily remembered, the northern entrance by the name of Jemappes, the southern by the name of Malplaquet. Villars no sooner knew what was going forward than he pushed forward a detachment with Aug. 27./Sept. 7. all speed upon the northern entrance, which was the nearer to him. The detachment came too late. The Prince of Hessen-Cassel was already astride of the opening, his right at Jemappes, his left at Ciply. The French thereupon fell back to await the approach of the main army of the Allies.
Aug. 26./Sept. 6.
Meanwhile that army had toiled through a sea of mud on the northern bank of the Haine, and crossing the river had by evening invested Mons on the eastern side. On the following day Villars and his whole army Aug. 27./Sept. 7. also arrived on the scene and encamped a couple of miles to westward of the forest-barrier, from Montreuil to Athis. Here he was joined by old Marshal Boufflers, who had volunteered his services at a time of such peril to France. The arrival of the gallant veteran caused such a tumult of rejoicing in the French camp that Marlborough and Eugene, not knowing what the clamour might portend, withdrew all but a fraction of the investing force from the town, and, advancing westward into the plain of Mons, caused the army to bivouac between Ciply and Quévy in order of battle.
Aug. 28./Sept. 8.
Villars meanwhile had not moved, being adroit enough to threaten both passages and keep the Allies in doubt as to which he should select. While, therefore, the mass of the Allied army was moved towards the Trouée d’Aulnois, a strong detachment was sent up to watch the Trouée de Boussut. That night Villars sent detachments forward to occupy the Aug. 29./Sept. 9. southern passage, and by mid-day of the morrow his whole army was taking up its position across the opening. Marlborough at once moved his army forward, approaching so close that his left wing exchanged cannon-shot with Villars’s right. Everything pointed to an immediate attack on the French before they should have time to entrench themselves. Whether the Dutch deputies intervened to stay further movements is uncertain. All that is known is that a council of war was held by the commanders of the Allies, and that, after much debate, it was resolved to await the arrival of the detachment from the Trouée de Boussut and of the troops that had been left behind at Tournay, to turn the siege of Mons into a blockade, and in the meanwhile to send eighteen battalions north to capture St. Ghislain. Evidently in some quarter there was reluctance to hazard a general action.
Villars now set himself with immense energy to strengthen his position; and, when Marlborough and Eugene surveyed the defences at daybreak of the Aug. 30./Sept. 10. following morning, they were astonished at the formidable appearance of the entrenchments. Marlborough was once more for attacking without further delay, but he was opposed by the Dutch deputies and even by Eugene. The attack was therefore fixed for the morrow; and another day was lost which Villars did not fail to turn to excellent account.
The entrance from the westward to the Trouée d’Aulnois or southern entrance to the plain of Mons was marked by the two villages of Campe du Hamlet on the north and Malplaquet on the south. About a mile in advance of these villages the ground rose to its highest elevation, the opening being about three thousand paces wide, and the ground broken and hollowed to right and left by small rivulets. This was the point selected by Villars for his position. It was bounded on his right by the forest of Laignières, the greatest length of which ran parallel to the Trouée, and on the left by a forest, known at different points by the names of Taisnières, Sart and Blangies, the greatest length of which ran at right angles to the Trouée. Villars occupied the forest of Laignières with his extreme right, his battalions strengthening the natural obstacles of a thick and tangled covert by means of abatis. From the edge of the wood he constructed a triple line of entrenchments, which ran across the opening for full a third of its width, when they gave way to a line of nine redans. These redans in turn yielded place to a swamp backed by more entrenchments, which carried the defences across to the wood of Taisnières. Several cannon were mounted on the entrenchments, and a battery of twenty guns before the redans. On Villars’s left the forests of Taisnières and Sart projected before the general front, forming a salient and re-entering angle. Entrenchments and abatis were constructed in accordance with this configuration, and two more batteries were erected on this side, in addition to several guns at various points along the line, to enfilade an advancing enemy. Feeling even thus insecure, Villars threw up more entrenchments at the villages of Malplaquet and Chaussée du Bois in rear of the wood of Sart, and was still hard at work on them to the last possible moment before the action. Finally in rear of all stood his cavalry, drawn up in several lines. The whole of his force amounted to ninety-five thousand men.
Stanford’s Geogl. Estabt., London.