Spaniards entered Tipai-Ipai territory in the late 18th century, bringing with them non-native, invasive flora, and domestic animals, which brought about degradation to local ecology. Under the Spanish Mission system, bands living near Mission San Diego de Alcalá, established in 1769, were called Diegueños. After Mexico took over the lands from Spain, they secularized the missions in 1834, and Ipai and Tipais lost their lands; essentially band members became serfs.
From 1870 to 1910, American settlers lawlessly seized lands, including arable and native gathering lands. In 1875, President Ulysses Grant created reservations in the area, and additional lands were placed under trust patent status after the passage of the 1891 Act for the Relief of Mission Indians. The reservations tended to be small and lacked adequate water supplies. www.wikipedia.com