The original route of the South Eastern Railway (SER) was from London Bridge station to Dover, which took a route through Redhill so that several companies could share the same lines and engineering (including a substantial tunnel) through the North Downs.

[5][6] From the start, the RG&RR was worked by the SER,[3] which leased it from 16 July 1846,[4] and absorbed it in 1852.

[7][3] When the first section of line opened, the SER trains served a temporary station north of Reading's Forbury Road before moving into a permanent terminal, about 275 metres (300 yd) west, on 30 August 1855.

The Staines, Wokingham & Woking Junction Railway (SW&WJR) opened a line between the existing London to Windsor line station of Staines in Middlesex (today in northern Surrey) and Wokingham in Berkshire on 9 July 1856; the SW&WJR was worked by the London and South Western Railway (LSWR), and they were authorised to run over the SER into Reading.

[12] At the opening, there were four trains a day to Redhill (then known as Reigate Junction), two of which continued to Tonbridge; a through service to London Bridge began in 1852, and in 1853, two more were added.

[17][18] During the Dunkirk evacuation (27 May-4 June 1940), 293 special trains arrived at Reading from the Channel ports, most of which were handed over to the GWR.

[23] Freight continued to be handled until September 1970, when all goods services were withdrawn except for the Huntley & Palmers biscuit traffic, which lasted until April 1979.

[12] After demolition the site of the passenger station was used as a car park for Reading General.

[25] A third connection to the east of the previous two was opened on 26 May 1941, and like the second allowed trains stopping in the GWR station to run to or from the SER line.

[32] The depot was reduced in importance in May 1954, when most of the locomotives were transferred away leaving just two shunting engines, but complete closure did not occur until January 1965.

[28][32] Since 1903 the Southern Railway and its constituents had pursued a policy of electrification, which began with the routes closest to the London termini and gradually worked outwards.

[34] The policy was continued by the Southern Railway from 1923,[35] and on 6 July 1930, electrification was extended to Windsor, which included the Reading line as far as Staines.

The first Beeching report recommended curtailing the passenger service at Guildford and the closure of all stations between Shalford and Betchworth inclusive.

[49][50] The second Beeching report recommended that the whole of the North Downs Line should be developed as a trunk route for freight services.

Instead, in 1964, six three-car trains were provided by putting together spare coaches from elsewhere on the network: twelve came from disbanded 6-S units on the Hastings line, six of which had Diesel engines and driving cabs; there were also six driving trailers from 2-EPB electric trains available.

Most trains consisted of one "tadpole" unit, but a few services were operated using BRCW Type 3 Diesel locomotives hauling three ordinary coaches.

The driver of the light engine and four passengers were killed; ten more were seriously injured, and three of those died later in hospital.