William Sadler, The Battle of Waterloo, 1815

Thackeray intertwines his characters' lives and fates with history in Vanity Fair, and the Battle of Waterloo is a decisive moment for the plot. This battle, a turning point in the war with France, took place on June 18, 1815 in Waterloo, Belgium, which was then part of the Netherlands. 

This great historical event that disrupts Becky's and Amelia's newlywed lives was a decisive victory for the allies over Napoleon Bonaparte. The Duke of Wellington led the charge of the Anglo-Allied army against troops under Napoleon's command.  The French numbered about 72,000; the British, German, and Dutch, under the Duke of Wellington, numbered 67,000.  Waterloo is the climax of the 100 days that began with Napoleon's escape from Elba.  Napoleon's seizure of power ended with the restoration of Louis XVIII on June 28, 1815.  Waterloo marks the end of the Napoleonic era and the rise of the British Empire.

In Vanity Fair, Thackeray elects to stay with the noncombatants, but he sends Rawdon Crawley (married to Becky Sharp), George Osborne (married to Amelia Sedley), and William Dobbin into the thick of battle.