The rail network in the UK is the oldest such network in the world. The system consists of five high-speed main lines (the West Coast, East Coast, Midland, Great Western and Great Eastern), which radiate from London to the rest of the country, augmented by regional rail lines and dense commuter networks within the major cities. High Speed 1 is operationally separate from the rest of the network. The world's first passenger railway running on steam was the Stockton and Darlington Railway, opened on 27 September 1825. Just under five years later the world's first intercity railway was the Liverpool and Manchester Railway, designed by George Stephenson and opened by the Prime Minister, the Duke of Wellington on 15 September 1830. The network grew rapidly as a patchwork of literally hundreds of separate companies during the Victorian era.