The Stockton & Darlington Railway (S&DR) was the first steam operated public railway in the world when it opened in 27 September 1825. The object of the railway was to reduce the cost of carriage of coal sent from the small coal mine in the Shildon area to Darlington & Stockton and at first it was not thought that there would be any need to provide facilities for passengers. For the first eight years the few passengers were carried in horse-drawn coaches operated by the contractors, it was not until 1833 that the company started to operate passenger trains hauled by locomotives. Synonymous with the S&DR are the names Pease and Stephenson. The Pease family, led by Edward Pease strongly supported the railway and Edward's son, Joseph, prepared the original prospectus and became the company's first treasurer. George Stephenson was appointed engineer in January 1822 to see to the survey and the building of the line, he also supplied the first locomotives which were built be his son, Robert Stephenson. In May 1825 Timothy Hackworth was appointed locomotive foreman and worked with the company for eight years and designed a type of locomotive more suitable for coal traffic, with six-coupled wheels. Most of the branches and extensions to the Stockton and Darlington Railway were built by separate companies, although worked by the S&DR, however most of these companies were taken over by S&DR in 1858. In 1863 the Stockton & Darlington Railway ceased to exist as a separate concern, but until 1876 it was run as the Darlington section of the North Eastern Railway.

The North Eastern Railway Company was formed in 1854 when the York, Newcastle and Berwick, York and North Midland, Leeds Northern, and Malton and Driffield Railways amalgamated. It acquired the West Hartlepool Railway in 1864, the Stockton and Darlington in 1865 and the Blyth and Tyne in 1874. As a result it almost had a monopoly in its area. Its area of operation covered the north east and north Yorkshire, and stretched from Berwick-on-Tweed south to Doncaster, with extensions into Westmorland and Cumberland and into Scotland. It exercised running powers over the North British line from Berwick to Edinburgh and a joint owner of the Forth Bridge. It was also a joint owner of the East Coast Joint Stock with the Great Northern and North British Railways. Its main goods traffic was coal from the Northumberland and Durham coalfields. It was an early investor in electrification, initially to deal with a difficult approach to the docks but later extended to the Newcastle-upon-Tyne suburban area. It also electrified goods workings between Shildon and Middlesbrough and planned to electrify the York to Newcastle route (even building a prototype locomotive) but the first world war intervened and the work was not carried out. The headquarters of the NER were in York where it also had its carriage works. The main works were at Shildon. Among its Chief Mechanical Engineers were Wilson Worsdell, Thomas Worsdell and Vincent Raven. The NER became part of the London and North Eastern Railway under Grouping in 1923.

The London and North Eastern Railway (LNER) was one of the four railway companies that were formed in 1923 due to the amalgamation of 1921. During the First World War the government had taken control of the railways for the purpose of the war effort. After the war ended it was decided that the railway companies could not competitively return to their prior state, and so the decision was made to combine the 120 existing railway companies into four companies, which became known as ‘the big four’. Smaller railway companies were merged together to form LNER, these previous companies consisted of; Great Central Railway, Great Eastern Railway, Great Northern Railway, Great North of Scotland Railway, Hull and Barnsley Railway, North British Railway and the North Eastern Railway. LNER was the second largest company of the ‘Big Four’ in terms of route miles (total route mileage amounted to 6700) and became famous for its prestigious high speed trains, including the Flying Scotsman and the Mallard, which reached speeds of 126mph (breaking the world record for steam). William Whitelaw, who was a public figure in Scotland, was appointed the first chairman of LNER operating mainly from the London headquarters. The management of LNER was decentralised as much as possible and one of Whitelaw’s main responsibilities became scrutinising proposals of expenditure, due to the shortage of investments. It was decided that the head of management should be Sir Lewis Wedgewood and it was under his management that three main headquarters should be created to best oversee the company. These areas were; Southern, North-Eastern, with offices being situated in York, and Scotland, which was then divided into Northern and Southern Scotland. By 1928 organisation in LNER had stabilised with the chairman being based in Marylebone, Chief General Manager being based in Kings Cross and the Southern headquarters being based in Liverpool. Sir Nigel Gresley became the first Chief Mechanical Engineer of the company. Each of the big four had a Chief Mechanical and Electrical Engineering department which was formed in 1923 with the creation of each company and after nationalisation in 1948, one CM&EE department was created. Gresley became very influential in the company, not only due to his designs of the Flying Scotsman and the Mallard, but also his Pacific designs and long-distance locomotives with the ability to overcome difficult operating conditions. Gresley died in office in 1941 and was succeeded by Edward Thompson, who remained CME until 1946. Arthur Peppercorn, a student of Gresley’s, succeeded Thompson but remained CME for just 18 months, as nationalisation cut short his career. After the Second World War all four railway companies were in financial trouble. The growth of road transport and the effects of the war had meant that each company was in need of severe maintenance work (LMS calculated it would have to spend £40 million on maintenance). Investors of the railways were also at a loss, the LNER’s investors had received no dividend since 1941. With the arrival of a new labour government in 1945, the decision to nationalise all public transport was put forward and in 1948 the ‘Big Four’ were replaced with the British Transport Commission, which separated LNER into Eastern and North Eastern Regions, as well as surrendering the Scottish territory.

Railways in Britain were nationalised under the terms of the Transport Act 1947 which came into effect on 1 January 1948. The Railway Executive, a corporate body subordinate to the British Transport Commission, was created to manage and operate the railways. It divided them into six geographical regions, largely based on the areas served by the pre-nationalisation railway companies. Between 1948 and 1952 the regional manager of the North Eastern Region was responsible to the Railway Executive for day to day operations in his region. After the Railway Executive was abolished in 1952, he reported to the British Transport Commission (BTC). In 1963, BTC itself was abolished and replaced by British Railways Board (BRB). Between 1963 and 1968 was a statutory board in accordance with the provisions of the Transport Act 1962, subordinate to and reporting to BRB. The North Eastern Region was a near direct post-nationalisation descendant the London North Eastern Railway (LNER) and covered a similar geographic area . The former LNER lines in England were subdivided into the Eastern Region and the North Eastern Region. The North Eastern Region covered everything east of the Pennines from the Humber to the Scottish border including the northern section of the east coast main line (York, Newcastle and Berwick). The main lines included the northern LNER lines in England and all ex-LMS lines east of Skipton. With both Hull and the Tyne ports and the industrial areas of Yorkshire, Durham and Northumberland this region handled a considerable quantity of heavy freight. In 1958 in a major re-drawing of the region boundaries The North Eastern Region gained former London Midland Scottish (LMS) lines that lay in the present-day West and North Yorkshire. The North Eastern Region was disbanded and merged with the Eastern Region in 1967 and the region's headquarters in York became the new headquarters.