The Metropolitan Railway became the first underground railway when it opened in London in 1863.
Its initial route connected Paddington with Farringdon, passing through stations that included Baker Street and King’s Cross. The line was built mainly in a shallow cut-and-cover trench and operated steam-hauled trains.
The railway was created to relieve congestion caused by road traffic and the growing number of commuters travelling into central London. Its success encouraged the construction of additional underground lines and helped shape the modern London Underground network.
The Metropolitan Railway is sometimes confused with the first deep-level electric railway. That distinction belongs to the City and South London Railway, which opened later in 1890.