About five thousand men had fallen on either side in this fierce engagement: but, heavy as was Wellington's loss, the firmness of the English army had already done much to foil Napoleon's effort at breaking through the line of the Allies. Blücher's retreat however left the English flank uncovered; and on the following day, while the Prussians were falling back on Wavre, Wellington, with nearly seventy thousand men--for his army was now well in hand--withdrew in good order, followed by the mass of the French forces under the Emperor himself. Napoleon had detached thirty thousand men under Grouchy to hang upon the rear of the beaten Prussians, while with a force of eighty thousand he resolved to bring Wellington to battle. On the morning of the 18th of June the two armies faced one another on the field of Waterloo in front of the Forest of Soignies, on the high road to Brussels. Napoleon's one fear had been that of a continued retreat. "I have them!" he cried, as he saw the English line drawn up on a low rise of ground which stretched across the high-road from the château of Hougomont on its right to the farm and straggling village of La Haye Sainte on its left. He had some grounds for his confidence of success. On either side the forces numbered between seventy and eighty thousand men: but the French were superior in guns and cavalry, and a large part of Wellington's force consisted of Belgian levies who broke and fled at the outset of the fight. A fierce attack upon Hougomont opened the battle at eleven; but it was not till midday that the corps of D'Erlon advanced upon the centre near La Haye Sainte, which from that time bore the main brunt of the struggle. Never has greater courage, whether of attack or endurance, been shown on any field than was shown by both combatants at Waterloo. The columns of D'Erlon, repulsed by the English foot, were hurled back in disorder by a charge of the Scots Greys; but the victorious horsemen were crushed in their turn by the French cuirassiers, and the mass of the French cavalry, twelve thousand strong, flung itself in charge after charge on the English front, carrying the English guns and sweeping with desperate bravery round the unbroken squares whose fire thinned their ranks. With almost equal bravery the French columns of the centre again advanced, wrested at last the farm of La Haye Sainte from their opponents, and pushed on vigorously though in vain under Ney against the troops in its rear.