Everyone knows that Cinco de Mayo, May 5th, is a Mexican holiday, one increasingly being celebrated in the United States. But not many know why that date is important.
The day marks a battle between French invaders and Mexicans defending the city of Puebla. Some 6,000 French troops under General de Lorencez besieged Puebla, which was defended by 2,000 Mexican soldiers commanded by General Ignacio Zaragoza. On the 5th of May in 1862 the French tried to storm the Mexican defenses. The Mexicans resisted robustly, inflicting heavy casualties on the French, who then withdrew.
What were French forces doing in Mexico? Mexico had defaulted on debts, and the French emperor Napoleon III used that as an excuse to invade Mexico. Napoleon sought to impose a Hapsburg emperor on Mexico. He chose Maximilian, an Austrian Archduke, who was the younger brother of Emperor Franz Josef of Austria.
Maximilian ruled as Emperor of Mexico from 1864 to 1867, supported by French bayonets rather than Mexican approval. The French finally withdrew in 1867. Maximilian was captured, and died with conspicuous bravery in front of Mexican firing squad.
Cinco de Mayo eventually became a day celebrating a Mexican triumph over French invaders. It never became a major holiday in Mexico, but in the last several decades has come to be a holiday for Americans of Mexican descent.