BATTLE OF WATERLOO 18th June 1815 After Napoleon's return from Elba and the start of his last 100 days of rule,he quickly assembled a new army and advanced into Belgium to face the Prussian army under Blucher and the British army unedr Wellington. He won two quick battles at Quatre Bras and Ligny, splitting the Prussians and British. he then advanced and met the British at Waterloo. The day was an affair of bloody French frontal infantry assaults and unsupported French cavalry charges. The British lines wavered but held firm, whilst the Prussians returned and started to pressure the French right wing. The French army sent in a final attack of the Imperial Old Guard to crack the British line. But for once these veterans failed and the French and Napoleon lost the battle.