The North British Railway was a British railway company, based in Edinburgh, Scotland. It was established in 1844, with the intention of linking with English railways at Berwick. The line opened in 1846, and from the outset the company followed a policy of expanding its geographical area, and competing with the Caledonian Railway in particular. In doing so it committed huge sums of money, and incurred shareholder disapproval that resulted in two chairmen leaving the company.

The Caledonian Railway (CR) was a major Scottish railway company. It was formed in the early 19th century with the objective of forming a link between English railways and Glasgow. It progressively extended its network and reached Edinburgh and Aberdeen, with a dense network of branch lines in the area surrounding Glasgow. It was absorbed into the London, Midland and Scottish Railway in 1923. Many of its principal routes are still used, and the original main line between Carlisle and Glasgow is in use as part of the West Coast Main Line railway.