The first Roman Catholic churches in the current territory of the Diocese of San Diego were two of the twenty-one "California Missions" (Mission San Diego de Alcala and Mission San Luis Rey de Francia). The area was first included in a diocese in 1840, with the creation of the Diocese of Both Californias (serving the entirety of the Mexican colonial provinces of Baja California and Alta California). After the conquest of Alta California by the United States, that diocese was divided, with the American portion becoming the Diocese of Monterey, later renamed the Diocese of Monterey-Los Angeles. In 1922, the diocese was again divided, with the southern portion becoming the Diocese of Los Angeles-San Diego.