It was authorised in 1836 but it found it very hard to raise money for the construction, and it opened only a part of its line, between Swindon and Cirencester, in 1841.

It sold its business to the Great Western Railway, which quickly built the line through to Gloucester in 1845 and Cheltenham in 1847; part of that route was shared with other companies.

From 1903 the route introduced railmotors, small self-powered coaches, that enabled the opening of numerous low-cost passenger stopping places.

It was operated as a horse-operated plateway of 3 ft 6 in (1,067 mm) gauge, chiefly intended to bring building stone down from quarries at Leckhampton, and to carry coal and other supplies from the docks then under construction at Gloucester.

Cheltenham was growing in importance due to the supposed healthy qualities of the waters, which encouraged well-to-do residents to settle there.

The engineer was Isambard Kingdom Brunel and the line was to be built on the broad gauge and it would use locomotive power.

[2] Birmingham promoters could see that if they could build a railway from their city to Gloucester, onward river-borne transport would connect with Bristol, at the time an important port serving the transatlantic trade.

[3] Even before the Great Western Railway had been authorised, people in Cheltenham had determined to promote a line from Cheltenham through Gloucester and Stroud to join the planned Great Western Railway near Swindon; they appointed Isambard Kingdom Brunel as their engineer, and he advised that a suitable line could be built.

[4] Accordingly they submitted a bill for the Cheltenham and Great Western Union Railway in the 1836 session of Parliament.

[5][7] Squire Gordon of Kemble, near Cirencester, made considerable objection to the railway and had to be bought off with a substantial cash sum in compensation.

[5][4] Contracts for construction were let in May 1837, and some investigatory work was done for the Sapperton Tunnel, but in November 1837 the C&GWUR reported that the condition of the money market was such that they were going to be unable to build all of their line in the foreseeable future.

[6] The C&GWUR decided to alter its priorities, and it let contracts for construction and acquired land at Gloucester for the station.

In the new situation, it was in the same position as the Birmingham company, and together they agreed to purchase the C&GWUR, together promoting a bill for the purpose in the 1840 session of Parliament.

[8][6] Meanwhile the C&GWUR had managed to construct its southern portion from Swindon to Cirencester; it was double track as far as the intended junction at Kemble and then single.

[8][4][6] The C&GWUR Board had become exhausted by the struggle to get this far and in 1842 they obtained the Cheltenham and Great Western Union Railway Act 1842 (5 & 6 Vict.

in 1844, which also authorised an extension at Cheltenham from the Lansdown station to a more central location at St James Square.

General Pasley, in making an inspection for the Board of Trade, enumerated them as follows: Lewis records that there were nineteen timber structures (that is, viaducts and ordinary overbridges and underbridges) on the line, all of them in the Stroud Valley.

[11] Captain Simmons of the Board of Trade inspected the line, the first important instance of a mixed gauge railway,[note 1] and reported on 15 October 1847.

The inspection included the newly constructed Avoiding Line, forming the third side of a triangle at Gloucester.

)[13] From the opening of the C&GWUR there was a conventional broad gauge junction at Standish, where the Bristol and Gloucester Railway converged.

On 25 July 1908 the junction was reopened, enabling GWR trains from Birmingham via Honeybourne to get access to the Bristol line.

On 26 October 1964 the converse crossovers were commissioned, enabling trains from the Stroud direction to run to the former Midland Railway northbound track and vice versa.

[14] In 1902, Thomas Nevin made application to construct light railways – in effect street passenger tramways – from Cheltenham to Gloucester, Stroud and Chalford.

Nevin's application was refused, but the GWR noted that road omnibus competition was already significant and frequent, while their own daily passenger service between Stonehouse and Chalford consisted of only five trains one way and six the other.

The GWR had been developing their own design alternatives for some time; a petrol version had been favoured in April 1903, as it might save the cost of a fireman.

The vehicles had retractable steps to allow passengers to board and alight at ground-level stopping places; some of these were simply level crossings.

The railmotors were progressively converted to trailers and used with conventional small locomotives fitted with push and pull apparatus, and the service was extended to run from Chalford to Gloucester.

The approach from the north was more difficult, climbing at 1 in 330 to 1 in 276 from Standish, then 1 in 250 from Stroud, and 1 in 75 and 1 in 60 for over three miles from St Mary's Crossing Halt.