West Ham United Football Club are based in Stratford, Newham, east London. They played home matches at the Boleyn Ground in Upton Park between 1904 and 2016, and moved to the London Stadium for the start of the 2016–17 season. The club's formative roots stretch back to their formation as a professional side in 1900, but existed for at least five years prior to this under the name Thames Ironworks F.C. who themselves were built upon the remains of Old Castle Swifts F.C. (a club formed in 1892).