To the surprise of the Allied army (chorus of “Strewth!” – or words to that effect from the rank and file and “Damn clever these Froggies!” from the officers) the morning of 18th June revealed that French engineers had tunnelled under Hougument in the night and rolled the whole complex 3-400 yards nearer the Charleroi-Brussels road.
The Anglo Dutch army was drawn up behind the ridge and the French had only the vaguest idea where they were. Accordingly they themselves decided they would make only a holding attack in the centre while making a double envelopmentand rolling up the two Allied flanks. This might have worked on the eastern flank where the Allies were weakest but in the west around Hougument they were at their stongest.
The French plan began to develop as the two attacking corps moved towards their respective flanks.at almost the same time news of the capture of a Prussian officer revealed to Napoleon that far from being many miles away and blocked from reaching the battlefield, his own casual approach to things the day before had allowed Blucher to escape immediate pursuit by Grouchy and he was already nearing the Waterloo position. With now uncharactistic decision he ordered a cushion fastened to his saddle and, with many an “Ouch!” and a “Merde!” he mounted and rode towards the east with his entire Guarde.
The attacks on the two outposts began but the garrisons in both resisted valiantly and well, throwing back assault after assault, even though the infantry was seconded by artillery fire and they took a steady toll on their attackers. Meanwhile D’Erlon was reaching the far left of the Allied deployment and preparing for his attack. He now had to reduce Papelotte but this was to prove as hard a nut to crack as hougument, which was slowing the movement on the other flank to a crawl and causing a steady leak of casualties to Reille’s corps (a Belgian ulcer?)