The Temecula massacre took place in December 1846 east of present-day Temecula, California. It was part of a series of related events in the Mexican–American War. A combined force of California militia and Cahuilla Indians attacked and killed an estimated 33-40 Luiseño Indians. The Mexicans took the military action in retaliation for the Indians' killing 11 Californio lancers, in what was called the Pauma Massacre.
In a conflict that was part of the Mexican–American War, in the Battle of San Pasqual on December 6, 1846, Andrés Pico led a force of Californios against the United States. Soon after, a small group of the Mexican/Californio lancers requisitioned horses from the Pauma band for the war. The Luiseño Indians murdered the eleven Californios from Pico's forces in retaliation, in what became known as the Pauma Massacre. When the Mexican General José María Flores in Los Angeles learned about this challenge to Mexican authority, he sent José del Carmen Lugo from San Bernardino with a force of men to capture and execute the tribal leaders responsible.
While en route to the Temecula Valley, Lugo encountered Chief Juan Antonio, leader of a group of Cahuilla Indians, who joined his forces. The two groups set up camp along the Santa Gertrudis Creek. Lugo was to wait for reinforcements from Los Angeles. Learning that José Ramón Carrillo and a group of men were at the Mission San Luis Rey de Francia, Lugo requested him to provide assistance. Carrillo and his men joined Lugo and Chief Antonio. Word reached the Temecula village that Californios from Los Angeles were headed to the valley. The Luiseñno went east into the canyon and hid.