The Midland main line from London St Pancras to the north of England is one of Britain's most important trunk routes. With its various loops and branches, this major artery of communication links busy centres of population such as Leicester, Derby, Nottingham, Sheffield, Manchester and Leeds. Notwithstanding its obvious importance as a busy main line, the Midland route was built in piecemeal fashion, the various sections (from London northwards) being the Midland Railway London Extension (opened 1868); the Leicester & Hitchen Railway (1857); the Midland Counties Railway (1840); and the North Midland Railway (1840). In recent years the Midland line has been regarded primarily as a link between London and Sheffield, although a number of services have continued to run through to Leeds, Manchester and other destinations in the north of England. However, during the Midland Railway period the best trains had run northward beyond Leeds, and thence along the spectacular Settle & Carlisle route which, in turn, provided a direct link to Scotland via the Glasgow & South Western Railway. Prestigious Anglo-Scottish trains no longer run on the Midland main line, but this historic route remains in operation as a vital part of the national railway system.