Authorised on 8 May 1833, the London & Birmingham Railway was one of Britain's first great trunk lines. Engineered by Robert Stephenson (1803-1859), the L&BR line was regarded at the time of its construction as 'the Eighth Wonder of the World'. The route was opened in stages; the first section from Euston to Boxmoor was brought into use on 20 June 1837. The route was extended to Tring on 16 October 1837, and on 9 April 1838 further sections were opened from Tring to Denbigh Hall and between Rugby, Coventry and Birmingham. Finally, on 17 September 1838, the L&BR route was completed throughout its 112-mile length. In its original form, the L&BR functioned as a transport link between London and Birmingham, but the establishment of long-distance railway communication between London and Scotland was regarded as a matter of national importance, and further companies such as the Grand Junction Railway and the Lancaster & Carlisle line were brought into existence to facilitate this ambitious aspiration. Although the L&BR was, at first, suspicious of these new companies, the London & Birmingham directors eventually decided to co-operate, and by 1846 the major west coast companies had amalgamated to form the 'London & North Western Railway' with the West Coast Main Line from Euston to Glasgow being one of the busiest railways in Britain, if not the world.