One side intercepted a message betraying the position of their enemy's ally at St. Lambert after launching a diversionary attack on a farmhouse at Hougoumont to begin this battle.  
When an officer asked for reinforcements, one general in this battle said, "Do you want me to make some?"  That general in this battle sent his personal bodyguards to recapture Plancenoit in an attempt to split the enemy's forces.  One side intercepted a message betraying the position of their enemy's ally at St. Lambert after launching a diversionary attack on a farmhouse at Hougoumont to begin this battle.  Marshal Ney mistakenly thought the other side was retreating and ordered a costly charge against La Haye Sainte.  One side in this battle was bolstered by troops led by Gebhart von Blucher.  Ending the Hundred Days, FTP, name this battle where the Duke of Wellington handed Napoleon his final defeat.
When an officer asked for reinforcements, one general in this battle said, "Do you want me to make some?"  
Battle of Waterloo