[2][3][4] Known as the Rancho del Rey (Ranch of the King) under Spain, this land west of the Presidio of Santa Barbara served since 1816 as a presidial cattle grazing ground.
In 1837, the six square league Rancho San Julian land grant was made by Governor Juan Bautista Alvarado to George Rock acting for José de la Guerra.
With the cession of Alta California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.
Severe drought and financial burdens forced the de la Guerra family to mortgage the property to Gaspar Oreña (1824–1904).
As of 2023, Thomas and Francesca de la Guerra Dibblee's descendant Elizabeth Poett has filmed three seasons of a cooking show, Ranch to Table, on Rancho San Julian for the Magnolia Network, featuring scenes from the ranch.