The Metropolitan District Railway (commonly known as the District Railway) was a passenger railway that served London from 1868 to 1933. Established in 1864 to complete the inner circle, an underground railway in London, the first part of the line opened using gas-lit wooden carriages hauled by steam locomotives. The Metropolitan Railway operated all services until the District introduced its own trains in 1871. The railway was soon extended westwards through Earl's Court to Fulham, Richmond, Ealing and Hounslow. After completing the inner circle and reaching Whitechapel in 1884, it was extended to Upminster in Essex in 1902.