On the 18th of August, 1914, the 9th Line Regiment was entrusted with protecting the right flank of the campaign army, which was falling back in the direction of Antwerp. The regiment left Kessel-Loo at 2.30 in the afternoon, reached Aerschot at 7 o'clock and took up its position to the north, on the right bank of the Démer. The 1st Battalion faced the Aerschot-Hersselt road; the 2nd, a little to the east, defending Doorenberg, a country house, inhabited in time of peace, it is said, by a German officer; the 3rd was first held in reserve, but after reconnaissance of the place, two of its Companies fell back, in order to rally the 1st and 2nd Battalions and cover the retreat. The information which reached us, from time to time, was to the effect that the Germans were advancing by the Aerschot-Hersselt road, occupied by the 4th Company of the 1st Battalion. The Commander, Captain Gilson, an officer of great bravery, who had given proof of what he was capable in the Congo, at once endeavoured to consolidate his position by defence works; barricades, beams, and heaps of earth were brought to obstruct the level crossing of the Antwerp-Hasselt railroad; barbed wire was stretched across the threatened road, the plains of which could be swept by two machine-guns, placed on the right and left and protected by grass earthworks.
As to the Company, it was disposed in the following manner: the 1st Platoon, under Lieutenant Fauconier, was ranged along the Aerschot-Herenthals railroad; the 2nd Platoon, under Lieutenant Jacquet, and the 3rd Platoon, under Adjutant Theys, took up their position along the curved embankment of the Hersselt road, one of them guarding the west sector and the other the east. A watch-out post, composed of twelve men, under the command of First Sergeant Scheenaerts, was placed six hundred yards away from milestone 2, near the Aurondenberg Mill, to the summit of which an observer climbed. Finally, sentinels and patrols went on further to the front and were stationed on the flanks, in order to avoid surprises of any kind.
On the 19th of August, towards five o'clock in the morning, the observer signalled the approach of a column of German Infantry and Cavalry on the Hersselt road. Their scouts soon reached our watch-out post, which fell back. In the distance, could be heard the characteristic sound of the artillery guns rolling along the pavement.
The enemy's advance guard stopped at the border of the woods, about four hundred yards to the north of the railway, whilst, at the extreme right, six scouts continued their advance in the direction of the level crossing. Commander Gilson told his sharp-shooters to keep in hiding and to let the enemies approach. When he saw them about a hundred yards away, he seized his gun, aimed calmly and deliberately, and brought down three Boches, one after the other. The three others, alarmed, threw themselves into a ditch. Fresh scouts, in greater number this time, replaced them immediately, and the German vanguard Company deployed to the east and west of the road and commenced firing. The Belgians did not reply, but when the enemy, scarcely attempting any concealment, made a bound forwards all along its line, Gilson commanded the opening of fire with rifles and machine-guns. The aim of the latter was so remarkable and so precise that the Commander could not help crying out "Bravo" to the nearest gunner. Under this avalanche, the enemy Company was almost wiped out.
From this moment, the Germans never ceased sending reinforcements to the right and left of their initial deployment. They emerged from the woods, at about three hundred or four hundred yards to the north of the Belgian line, but, as soon as they were in the open, their march was stopped by the fire of their adversaries. Four Companies attempted the passage in vain and retreated into the woods, leaving a great number of their men on the plain. Towards four in the afternoon, the German Artillery, placed beyond the crest of the hill, probably near milestone 3, opened fire, first on the border of the wood to the north of Aerschot, then more to the south, on the town itself. Some of the shells burst in the Belgian line. Half an hour later, two German machine-guns were put into action and one could hear their "Ta-ra-ta-ra" distinctly in the midst of the detonations of the musketry. On account of the absence of any smoke, though, the Belgians could not discover their exact position.
Finally, Commander Gilson, with his field-glasses, caught sight of one of the enemy machine-guns on a heap of wood. An observer, crouching down, gave the necessary indications to our gunner. He, in his turn, passed the information on for the machine-gun nearest him and to a few sharp-shooters, and, in a few minutes, the German gun was reduced to silence.
The Boches brought up another one, and, in spite of its proximity, Gilson had the greatest difficulty in locating it. As soon as he had done so, thanks again to his field-glasses, he directed the firing himself and brought down two of the enemy gunners.
As they could not succeed in breaking through the Belgian front, the Germans now executed a turning movement in the direction of our left. Three or four Companies crept along the west embankment of the Herenthals railway, whilst other troops came out from the De Heide Woods, situated still farther west. The Artillery, too, came nearer and took position at about seven hundred yards away, on the side of the Mill, the gallery of which concealed an observer. Four guns then executed a rapid firing of shrapnel exactly over the Belgian line; the others continued bombarding the town of Aerschot and its outskirts. On the crest of the hill, to the east, could be seen the outline of grey masses on the way down. In order to oppose this turning movement, and to prevent the enemy cutting him off, Colonel Flébus, in command of the 9th Line Regiment, sent a Company to occupy the railway line behind Aerschot, at the height of the milestone 23. He would have a safe retreat there, if the position became impossible.
The enemy was concentrating its chief effort, though, on the 4th Company of the 1st Battalion, the men of which had been sustaining a very unequal fight for several hours. Commander Gilson sent a note to the Major by a cyclist, notifying: "4/1 severely engaged. Germans outflanking us to the left. Can I count on a reinforcement?" This request was transmitted to the Colonel, who sent a Company to support the 4/1. In order to reach the spot occupied by Commander Gilson, this Company had to cross an open space which was being swept by the enemy Artillery established at Geymelberg. The firing to bar this way made it impossible for the reinforcement to advance. It was all in vain that the men endeavoured to hollow out shelters for themselves, rapidly, as the machine-guns raked the trenches, thus causing many victims. Under these conditions, the Colonel judged a retreat necessary and ordered the different Companies to fall back by the railway, under the protection of the troops placed there in reserve. The despatch bearers, with the order intended for the 4th Company, were killed on their way back, though, and Commander Gilson remained without instructions and without reinforcements. He saw the Companies, occupying his right leave, one after the other, in the direction of Aerschot.
The fate of this single troop, left alone to sustain the brunt of the enemy's onset, is told by Commander Gilson himself in the following words: