The Mexican authorities in California 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.
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.
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.
The Mormons stood guard to prevent further bloodshed while the Luiseño people gathered their dead into a common grave.