NAPOLEON, perceiving that BLÜCHER has scarcely any Reserve remaining at his disposal, resolves upon attacking the Prussian Centre 230 He suspends his meditated attack in consequence of a large Column advancing apparently from Frasne towards his Left Rear 231 This Column is discovered to be D'ERLON's _Corps d'Armée_ 234 This circumstance explained 234 THIELEMANN detaches a portion of his Cavalry with some guns across the Ligny, along the Fleurus road 237 They are attacked and driven back by part of GROUCHY's Cavalry 237 Disposition and state of the Prussian troops at the moment NAPOLEON advances with a formidable Reserve across the Ligny 239 The Prussian Infantry forced to evacuate Ligny 242 Failure of Prussian Cavalry attacks upon the advancing Column of French Infantry 243 BLÜCHER's horse is killed, and the Prince thrown under him 245 Critical situation of the Prussian Commander 246 He is removed from the Field 246 Retreat of Prussian Infantry upon Bry 247 Contest at Sombref 249 Retreat of the Prussians from St Amand and St Amand la Haye 250 ZIETEN's and PIRCH's Corps retire by Marbais and Tilly 251 THIELEMANN's Corps retains its position 252 Close of the Battle 253 Distribution of the French troops 254 Disposition of the Prussian troops 254 BÜLOW's Corps reaches Gembloux during the night 255 Losses sustained by both Armies 255 Consequences of the Prussian defeat 255 Remarks upon the Battle 256 CHAPTER VII. An engagement of short duration, and originating accidentally, takes place between the French and Anglo-Allied Picquets on the Field of Quatre Bras, about an hour before daylight of the 17th June 259 WELLINGTON detaches a Patrol to his Left for the purpose of gaining intelligence concerning BLÜCHER's movements 261 The Patrol finds the Prussians at Tilly 262 Upon its return WELLINGTON decides on retrograding his forces to the position in front of Waterloo 263 Order of Movement 263 Communications between BLÜCHER and WELLINGTON 264