Settlers in Sonoma began rebelling against Mexico, later proclaiming the California Republic and raising a homemade flag with a bear and a star.

Sonoma is a city in Sonoma County, California, United States, located in the North Bay region of the San Francisco Bay Area. Sonoma is one of the principal cities of California's Wine Country and the center of the Sonoma Valley AVA. Sonoma's population was 10,739 as of the 2020 census, while the Sonoma urban area had a population of 31,479. Sonoma is a popular tourist destination, owing to its Californian wineries, noted events like the Sonoma International Film Festival, and its historic center.

The California Republic, or Bear Flag Republic, was an unrecognized breakaway state from Mexico, that existed from June 14, 1846 to July 9, 1846. It militarily controlled an area north of San Francisco, in and around what is now Sonoma County in California.

The Bear Flag is the official flag of the U.S. state of California. The precursor of the flag was first flown during the 1846 Bear Flag Revolt and was also known as the Bear Flag. A predecessor, called the Lone Star Flag, was used in an 1836 independence movement; the red star element from that flag appears in the Bear Flag of today.