The 2nd Battalion sailed on the Bavarian about 18th January 1900, and arrived about 3rd February. Along with the 2nd Cheshire, 1st East Lancashire, and 2nd North Staffordshire, they formed the 15th Brigade under Major General A G Wavell, and part of the VIIth Division under Lieutenant General Tucker. For notes as to the general work of the division see 2nd Norfolk, and for that of the brigade see 2nd Cheshire.
In the advances to Bloemfontein and Pretoria the South Wales Borderers had never very desperate fighting.
After De Wet had broken out of the Brandwater basin the South Wales Borderers were brought down the line to Wolvehoek, partly to protect the railway and partly to assist in the pursuit of the Boer force. In this pursuit the battalion took part, the marching being very severe.
At the end of August 1900 the battalion was part of a column under Major General Hart which operated between Krugersdorp and Potchefstroom.
Twelve officers and 17 non-commissioned officers and men were mentioned in Lord Roberts' final despatch.
About 200 men of the battalion were the main part of a post at Modderfontein, in the Gatsrand, when it was attacked by a strong force at the end of January 1901. The garrison made a fine defence, but was forced to surrender before help arrived. The losses of the Borderers in the fighting about this time were 10 killed and about 40 wounded.
Eight men were mentioned in Lord Kitchener's despatches for exceptional gallantry, one gaining the distinguished conduct medal. One officer was mentioned for good work in a convoy fight on 23rd May 1901.
The battalion was mainly engaged in column or garrison work in the south-west of the Transvaal during the remainder of the campaign. Near its close they were stationed at Klerksdorp.
In the final despatch 3 officers and 3 non-commissioned officers were mentioned.
