The Great Western Railway (GWR) was incorporated by an act of Parliament in 1835 and nationalised on 1 January 1948. During this time it amalgamated with, or purchased outright, many other railway companies. These are listed here in two groups. The early amalgamations (mostly between 1843 and 1900) often involved railway companies that were already being financially supported by the GWR. The Railways Act 1921 brought many new companies into the fold including many successful Welsh lines.
List key
Company which amalgmated into the GWR (date of amalgamation)
Prior amalgmation into the above company
♠ – Companies that were already operated by or leased to the GWR or one of the other absorbed railways before amalgamation. Note: This list is incomplete.
‡ – Companies operating wholly or partly on the 7 ft 1⁄4 in (2,140 mm) broad gauge at the time that they combined with the GWR. The broad gauge was finally abandoned on 21 May 1892.
§ – Railways which were amalgamated before they opened to traffic.
The Railways Act 1921 provided for the compulsory amalgamation of many of Britain's railways. 27 of the larger railways (termed "Constituent Companies" by the act) would amalgamate on or before 1 January 1923 to create four larger railways (termed "Amalgamated Companies"). About 100 of the smaller railways (termed "Subsidiary Companies") would be absorbed by either the Constituent Companies or the Amalgamated Companies. In what was termed the "Western Group", the Constituent Companies were:
These amalgamated on 1 January 1922, and the company continued to use the name Great Western Railway, and its new board of directors included representatives from all seven of the constituent companies. There was no board representation for the Subsidiary Companies, which were:
After the grouping, two organisations voluntarily sold their operations and locomotives to the GWR. Both of these worked the railways of Swansea Docks:
^MacDermot, E T (1927). "Appendix 1". History of the Great Western Railway, volume I 1833-1863. London: Great Western Railway. Reprinted 1982, Ian Allan, ISBN0-7110-0411-0
^MacDermot, E T (1931). "Appendix 1". History of the Great Western Railway, volume II 1863-1921. London: Great Western Railway. Reprinted 1982, Ian Allan, ISBN0-711004-12-9
^"A brief review of the Company's hundred years of business". Great Western Railway Magazine. Great Western Railway. 47 (9): 495–499. 1935.
^The Railway Year Book for 1920. London: The Railway Publishing Company Limited. 1920. p. 154.
^The Railway Year Book for 1926. London: The Railway Publishing Company Limited. 1926. pp. 154–172.
