At 1300, Napoleon’s artillery was finally in position, and the 80 guns of the “Grand Battery” opened on Wellington’s line. Napoleon, a former artillery officer (imagine that), had made a career of smashing a portion of an adversary’s line with cannon and then following the through the rupture with dense columns of infantry acting as a human battering ram. Wellington knew this and placed the majority of his troops on the reverse slope of the Mont St Jean ridge, which protected them from the worst, but not all, of the cannon fire. The casualties began to mount.

At 1320, D’Erlon’s I Corps stepped off on the long march through the wet wheat fields, and finally Wellington’s artillery returned fire. For the next 30 minutes, the Allied troops stoically stood in formation and took it, while the French slowly marched forward and took it. On both sides, whenever holes appeared in the line, men from the rear ranks stepped into them. About 1345 pm, Wellington, fully within range of Napoleon’s guns (most of his staff would be casualties by the end of the day), commented,

“Hard pounding, gentlemen. Let’s see who pounds the longest.”

D’Erlon’s Corps first encountered the walled farm at La Haye Sainte and detached 7000 troops to assault it, as the rest continued on. The farm was held by 700 line infantry of the King’s German Legion. King George III of Britain (yes, that one) was not actually English, but German; his other title was King George of Hannover. The King’s German Legion were soldiers who fled Hannover to Britain when Napoleon conquered it in 1803 and they formed some of Wellington’s best troops. Major Georg Baring and his battalion proved a thorn in D’Erlon’s side for the next six hours.

Weathering round shot, canister shot, double canister, rifle fire, and finally the renowned disciplined musket fusillade from British infantry, D’Erlon’s 17,000 strong columns struck the British lines at 1400. D’Erlon knew his enemy though, and he concentrated his heaviest attacks on the least reliable of Wellington’s troops, the Belgians and Dutch. Wellington acknowledged this weakness and interspersed British and German units to stiffen their lines (just as he had done on the peninsula with the Portuguese and Spanish). However, the Dutch were hastily mobilized for this campaign and many of the Belgians fought for Napoleon previously, some for over ten years. After just 15 minutes, their lines cracked and then broke.

The rout of Wellington’s Belgians and Dutch in the center was Napoleon’s high watermark of the battle. Had D’Erlon had more troops, from any source, to secure the breach and prepare for the inevitable counterattack, the battle would almost certainly have been over. But after the long march under fire and the furious fight on the ridge, D’Erlon’s men by themselves couldn’t withstand a determined counter attack. Around 1430, the top hat and great coat clad Sir Thomas Picton led the 5th Division in a counterattack. Soon after, the British heavy cavalry moved forward to exploit the highlanders’ assault. Just after Picton unleashed his highlanders, the Earl of Uxbridge released the Household Brigade and the Union Brigade against the French. With La Haye Saint Sainte still under Allied control, the French had nowhere to rally, and the British cavalry swept the D’Erlon’s men from the field. The British cavalry was only stopped by French lancers and cuirassiers in a countercharge. Some of the British horsemen made it all the way to the Grand Battery.

D’Erlon was furious. His first attack nearly successful, and he inquired Ney as to why he wasn’t supported. His men would be forced to make the same attack again. Their ordeal was for nothing. Where was the cavalry? Bad staff work had them too far from the breakthrough. Where was the Imperial Guard? Napoleon jealously guarded their use. Where was Lobau and VI Corps? They were investigating a body of troops spotted six miles to the east.

The east? Blucher had arrived.