London has the world’s oldest underground railway, which opened in 1863.
The Metropolitan Railway began operating on 10 January 1863 between Paddington and Farringdon. It was built to relieve severe congestion caused by horse-drawn traffic and to connect mainline railway termini with the City of London.
The first trains were steam-hauled, so early underground travel was smoky and poorly ventilated. Electrification later made deeper tunnels and cleaner operation practical. The Metropolitan Railway and other companies eventually formed the network now known as the London Underground, commonly called the Tube.
London’s system is often confused with the world’s first electric underground railway, which opened later. Its historical distinction is priority: London’s underground railway began service decades before the metro systems of cities such as Paris, Berlin and Madrid.