The Battle of Puebla took place on May 5, 1862 near the city of Puebla, Mexico, during the French intervention in Mexico. It was a major Mexican victory, and is commemorated every year as Cinco de Mayo.

In late 1861, Napoleon III of France sent his troops to Mexico, supposedly to collect debts owed by a previous Mexican government. President Benito Juárez had agreed to pay these debts, but only in installments. The true goal of Napoleon III was to depose the Mexican Constitutional Government, set up a monarchy favorable to France, and then expand control to Central and South America.

Napoleon III's troops occupied the port city of Veracruz on December 8, 1861. The expedition's true goal soon became apparent.

The passes leading to Puebla were protected by Forts Guadalupe and Loreto. Zaragoza had linked the forts with defensive trenches dug across the road.

The weather favored the Mexicans. Rainy season downpours had turned the ground to mud, slowing the movement of the French artillery.

Contemptuous of the Mexican troops, General Lorencez assumed they would flee from heavy fighting. At noon, he directed his first charge at the Mexican center. The Mexicans held their ground and drove the French back. The French regrouped and launched two more charges, both defeated.

The Mexicans counter-attacked. A force of Zacapoaxtla and Xochiapulco Indians, many armed only with machetes, overran part of the French lines. Porfirio Díaz (a future President of Mexico) led a well disciplined company of Mexican cavalry that flanked the French. The battle was over by 4:30 p.m.

As darkness fell, the French pulled back some distance. General Lorencez waited two days for a Mexican counter-offensive, but Zaragoza did not want to attack the French in open country, where he would lose his defensive advantage. Unwilling to risk another attack and faced with inclement weather that included a hail storm, Lorencez withdrew his forces to Orizaba.

On May 10, 1862, President Juárez declared that the anniversary of the Battle of Puebla would be a national holiday, regarded as "Battle of Puebla Day" or just Cinco de Mayo. Although it is recognized as a day of celebration, nowadays it is not a federal holiday in Mexico, and whether or not people take time off school or work depends on the particular situation.

Realizing their expeditionary force was understrength for its intended task, the French reinforced it with an additional 30,000 troops. In 1863, the French again marched towards Mexico City, this time bypassing Puebla. Following their success in capturing the capital, they installed the puppet regime of Emperor Maximilian.

While the Battle of Puebla did not prevent the French takeover of Mexico, it was nonetheless an important victory for the Mexicans. It raised their morale and strengthened their determination to resist the invasion. It gave the Juárez government much needed time. While they were forced to abandon Mexico City and retreat to the north, they maintained a working government that many nations recognized as legitimate. In 1867, they defeated Maximilian and his allies.

The Battle of Puebla was also of historic importance in that it squashed Napoleon III's hopes of a quick takeover of Mexico, which he was planning to use as a base to aid the Confederates in the American Civil War

• History of Mexico
• Ignacio Zaragoza
• Cinco de mayo