[2] St Mark's was built to serve workers of the Great Western Railway, whose Swindon Works were nearby.

In February 1843, the railway company appealed for contributions from the public, and a total of £6,000 (equivalent to £750,000 in 2023)[3] was raised to build the church.

[2] The parish is within the Anglo-Catholic tradition of the Church of England, and rejects the ordination of women as priests and bishop.

The tower is in four stages, and has a north door, angle buttresses, and two-light louvred bell openings.

[6] St Mark's has a long tradition of performing choral music in the style of an English cathedral.

[7] In 1944 Benjamin Britten composed his Festival Te Deum for the centenary of the church, where it was first performed on 24 April 1945.

William was the youngest brother of Sir Daniel Gooch, trained as an engineer under him, and became manager of the GWR Works.

His funeral was held in the church on 9 June 1877, and on that day shops closed, special trains were put on and a temporary platform was built.