Marshall's Horse was a South African cavalry unit formed in 1899 at the start of the Second Boer War to provide military support for the British campaign.

Consequently, Marshall's Horse were stationed in Grahamstown and patrolled the surrounding railway network until the last months of 1899 when Schreiner was forced to concede.

[1][2] In early 1900, under Ridley's 4th Mounted Infantry Brigade, the Unit joined the British advance from the Modder River to Bloemfontein.

They were engaged at Doornkop, south-west of Johannesburg, on 29 May, and in the Battle of Diamond Hill, east of Pretoria, on 11th, 12th, and 13 June, and had slight casualties in both actions.

On 17 October 1900, as part of Major General Barton's column, six members of Marshall's Horse were cut off by Boers whilst collecting supplies near Frederickstad.

On 1 April 1901 The Melbourne Argus reported the incident as follows: "A disaster has befallen Marshall's Horse...a patrol of the corps was surrounded by an overwhelming Boer force...After the officer in charge had been killed and five men wounded, the others surrendered.

According to a memorial on the wall of St John the Baptist Church, Newport, Monmouthshire, 60 members of Marshall's Horse died during the Second Boer War.