The Battle of Puebla, celebrated by Cinco de Mayo, occurred in 1862.
The battle was fought on May 5 during the early phase of the French intervention in Mexico. Mexican forces under Ignacio Zaragoza defeated a French army commanded by Charles de Lorencez near Puebla. The victory slowed France’s advance and strengthened the position of Mexico’s republican government.
The year 1862 is sometimes mixed up with 1867, when French forces withdrew and Emperor Maximilian was executed after the republic was restored. Those later events ended the intervention, but they are not the event commemorated by Cinco de Mayo. The date celebrates the earlier Mexican victory at Puebla, not the final conclusion of the conflict.