June 18 - 1815 - The Battle of Waterloo
Something as famous and significant as the Battle of Waterloo has been debated and pored over so much that it would seem hard to summarize. Significantly, Waterloo inaugurated decades of peace across the European continent. More notably, Napoleon's defeat at Waterloo made the name "Waterloo" a by-word for ultimate failure or comeuppance. Despite this cultural currency, it is still unclear precisely what the lessons of the Battle of Waterloo should be.