When the clouds cleared, a little before sunset, this strongest veteran corps of Napoleon's army had done the business. Ligny was carried and held. The Prussian formation, from a convex line, was now a line bent inwards at its centre and all but broken. Blucher had rapidly returned from the right to meet the peril. He charged at the head of his Uhlans. The head of the French column of Guards reserved their fire until the horse was almost upon them; then, in volley after volley at a stone's-throw range, they broke that cavalry, which, in their turn, the French cuirassiers charged as it fled and destroyed it. Blucher's own horse was shot under him, the colonel of the Uhlans captured, the whole of the Prussian centre fell into disorder and was crushed confusedly back towards the Nivelles-Namur road. Darkness fell, and nothing more could be accomplished. The field was won, indeed, but the Prussian army was still an organisation and a power. It had lost heavily in surrenders, flight, and fallen, but its main part was still organised. It was driven to retreat in the darkness, but remained ready, when time should serve, to reappear. It kept its order against the end of the French pressure throughout the last glimmer of twilight; and when darkness fell, the troops of Blucher, though in retreat, were in a retreat compact and orderly, and the bulk of his command was saved from the enemy and available for further action. Thus ended the battle of Ligny, glorious for the Emperor, who had achieved so much success against great odds and after the hottest combat; but a failure of his full plan, for the host before him was still in existence: it was free to retreat in what direction, east or north, it might choose. The choice was made with immediate and conquering decision: the order passed in the darkness, "By Tilly on Wavre." The Prussian staff had not lost its head under the blow of its defeat. It preserved a clear view of the campaign, with its remaining chances, and the then beaten army corps were concentrated upon a movement northwards. Word was sent to the fresh and unused Fourth Corps to join the other three at _Wavre_, and the march was begun which permitted Blucher, forty hours later, to come up on the flank of the French at Waterloo and destroy them. QUATRE BRAS Such had been the result of the long afternoon's work upon the right-hand or eastern battlefield, that of Ligny, where Napoleon had been in personal command. In spite of his appeals, no one had reached him from the western field, and the First Corps had only appeared in Napoleon's neighbourhood to disappear again. What had been happening on that western battlefield, three to four miles away, which had thus prevented some part at least of Ney's army coming up upon the flank of the Prussians at Ligny, towards the end of the day, and inflicting upon Blucher a complete disaster? What had happened was the slow, confused action known to history as the battle of Quatre Bras.