Lafayette (formerly La Fayette) is a city in Contra Costa County, California, United States. As of 2010, the city's population was 23,893. It was named after the Marquis de Lafayette, a French military hero of the American Revolutionary War.
Before the colonization of the region by Spain, Lafayette and its vicinity were inhabited by the Saclan tribe of the indigenous Bay Miwok. Ohlone also populated some of the areas along Lafayette Creek. The indigenous inhabitants' first contact with Europeans was in the late 18th century with the founding of Catholic missions in the region. These initial contacts developed into conflict, with years of armed struggle, including a battle on what is currently Lafayette soil in 1797 between the Saclan and the Spanish, and eventually resulting in the subjugation of the native population.
Most of what is currently Lafayette was given as a Mexican land grant, Rancho Acalanes to Candelario Valencia in 1834. The name Acalanes seems to have come from the name of a native village in the area, Ahala-n.
American settlement started with the arrival of Elam Brown from St. Joseph, Missouri, in 1846.