When, on 1 January 1923, the Great North of Scotland Railway (GNoSR) merged with other railways to become the London and North Eastern Railway, it owned of line. Its main line, from Aberdeen in Scotland to Elgin via Keith, served branches to Fraserburgh and Peterhead, Alford, Oldmeldrum, Macduff, Banff, Boat of Garten and Lossiemouth. The GNoSR operated two routes to Elgin, one via Moray Firth, known as the Coast line, and another via Keith and Craigelliache; these connected with the Highland Railway at Keith and Elgin for services to Inverness. Another line, used by the reigning monarch when they travelled to Balmoral Castle, connected Aberdeen with Ballater.
Main line
The first section of Great North of Scotland's main line opened in 1854 from Kittybrewster to Huntly and was extended two years later to Keith. A through route to Inverness was formed in 1858 when was to become the Highland Railway reached the station and a junction was formed. Services ran to a terminus in Aberdeen at Waterloo from 1856 before Aberdeen joint station opened in 1867. The line was extended at the country end to Dufftown in 1862. Meanwhile, the Morayshire Railway had built a line from Rothes to Craigellachie, and subsequently linked this line to its Elgin station in 1862. This was connected to the GNoSR when the Strathspey Railway opened in 1863.
The GNoSR ran suburban services between Aberdeen and Dyce from 1887 and 1937. The old GNoSR main line west of Keith and the Coast line closed on 6 May 1968; on the same day services were withdrawn from minor intermediate stations. the Aberdeen to Inverness Line uses the former Great North of Scotland Railway line as far Keith, with intermediate stations at , , , and , before continuing over the former Highland Railway route to Inverness.
Buchan section
The Formartine and Buchan Railway built the from Dyce to Old Deer (renamed in 1867) via , which opened on 18 July 1861, Maud becoming a junction when the line to opened on 24 April 1865. The line was worked by the GNoSR from opening, who absorbed the original railway company on 1 August 1866. A branch from Ellon to and opened in 1897. The line was closed to passengers on 4 October 1965 and completely 8 October 1979.
Cruden section
The GNoSR opened a branch from Ellon to Boddam on 2 August 1897 to serve a hotel and golf complex it was building at Cruden Bay. The line closed to passengers on 31 October 1932 and completely on 7 November 1945.
Peterhead branch
The line from Dyce to Old Deer (renamed in 1867) was opened on 18 July 1861 by the Formartine and Buchan Railway, and extended the to the following year. The railway was worked by the GNoSR from opening, who absorbed the Formartine and Buchan on 1 August 1866. The branch closed to passengers on 3 May 1965 and completely in 1970.
St Combs Light Railway
The GNoSR opened the St Combs Light Railway from Fraserburgh to St Combs on 1 July 1903, and it closed on 3 May 1965.
Alford branch
The Alford Valley Railway from Kintore to Alford opened on 21 March 1859, worked by the GNoSR, with whom it merged on 1 August 1866. The line closed to passengers on 2 January 1950 and to goods in 1966.
Oldmeldrum branch
The Inverury and Old Meldrum Junction Railway from Inverurie to Old Meldrum opened on 26 June 1856, worked by the GNoSR, with whom it merged on 1 August 1866. The line closed to passengers on 2 November 1931 and to goods on 3 January 1966.
Macduff branch
Authorised in 1855 and sponsored by the Great North, the Banff, Macduff and Turriff Junction Railway opened a line from Inveramsay to Turriff in 1857, and another company, the Banff, Macduff and Turriff Extension built and opened an extension to Banff & Macduff nearly two years later. The railways were worked by the GNoSR from opening, and merged with it on 1 August 1866. The short extension to Macduff was opened by the GNoSR in 1872, the original terminal closed and demolished. The branch closed to passengers on 1 October 1951, the section north of Turriff completely on 1 August 1961 and completely on 3 January 1966.
