1815
Battle of Waterloo
The setting
Near Waterloo, south of Brussels, in present-day Belgium (then United Kingdom of the Netherlands)
An east-west ridge (Mont-Saint-Jean) bisected by the Brussels road, with a sunken Ohain road along the crest and fortified strongpoints at Hougoumont, La Haye Sainte, and Papelotte to the front.
Reveal the outcome
Recorded sideAnglo-allied army (Wellington) + Prussian army (Blucher)
Recorded resultdecisive Coalition victory
Decisive Coalition victory; the French army was routed
How the atlas explains it
Wellington's defensive use of the reverse slope and the fortified farms blunted repeated French assaults through the day, fixing Napoleon's army in place until Blucher's Prussians arrived on the French right flank, giving the Coalition decisive numerical superiority; the repulse of the Imperial Guard's final attack collapsed French morale.
What followed
Ended Napoleon's Hundred Days and his rule, brought the final collapse of the First French Empire, and opened a long period of relative peace in Europe.