About 6,000 French troops attacked Puebla in the Battle of Puebla in 1862.
The French expedition had entered Mexico after the Mexican government suspended payments on foreign debts. Britain and Spain eventually withdrew after negotiations, but France continued its intervention under Napoleon III. The French force advanced inland and reached Puebla in the spring of 1862.
Historical accounts usually describe the attacking force as approximately 6,000 soldiers. The number is an estimate, and different references may give slightly different totals depending on whether they count supporting units or only troops directly involved in the assault.
Despite their numerical advantage and reputation, the French failed to take Puebla on May 5. The Mexican defense relied on prepared positions, determined infantry, and successful counterattacks. France later returned with a much larger army, captured Puebla in 1863, and eventually occupied Mexico City.