Emperor Napoleon was defeated at the Battle of Waterloo by the Seventh Coaltion

1. Tennis scoring follows what at first may seem like an odd order of 15, 30, 40. However, one theory originates the scoring to medieval French where a clock-faced was used on the court to keep scoring. For convenience, the hand was moved a quarter of a turn (15minutes) for point one (15 minutes), two (30 minutes), and could have been moved another 15 minutes (45 minutes) for point three and a final 15 minutes (back the 0) for the fourth and final point of a game.
However, in event of a tie (deuce), a player needs to win by two points. Therefore, after the second point (30 minutes), the hand was only moved 10 minutes to 40 minutes. Now the next points would each move the clock by 10 minutes to 50 and 60. If the opposing player scores when a player is at 50, the hand is moved back to 40 minutes.
2. Battle of Waterloo was fought on June 18, 1815 near Waterloo in present-day Belgium (then park of UK). Emperor Napoleon was defeated at Waterloo by a combined armies of the Seventh Coalition consisting of Austria, Prussia, Russia and the United Kingdom. The defeat at Waterloo put an end to Napoleon's rule as Emperor of the French.