Santa Rosa (Spanish for '"Saint Rose"') is a city in and the county seat of Sonoma County. Its estimated 2019 population was 176,753. Santa Rosa is the largest city in California's Redwood Empire, Wine Country and the North Bay; the fifth most populous city in the San Francisco Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 27th most populous city in California.
Santa Rosa was founded in 1833 and named after Saint Rose of Lima. Before the arrival of Europeans, the Santa Rosa Plain was home to a strong and populous tribe of Pomo natives known as the Bitakomtara. The Bitakomtara controlled the area closely, barring passage to others until permission was arranged. Those who entered without permission were subject to harsh penalties. The tribe gathered at ceremonial times on Santa Rosa Creek near present-day Spring Lake Regional Park. Upon the arrival of Europeans, the Pomos were decimated by smallpox brought from Europe. By 1900 the Pomo population had decreased by 95%.
The first known permanent European settlement of Santa Rosa was the homestead of the Carrillo family, in-laws to Mariano Guadalupe Vallejo, who settled the Sonoma pueblo and Petaluma area.