The 5th and 6th contingents, approximately five squadrons strong, sailed early in March 1901. Major J R Royston, DSO, was appointed to command these contingents. He had begun the war as a Lieutenant in the Border Mounted Rifles—a Natal volunteer corps—and had gained distinction at the defence of Ladysmith. As will be seen from the Mentions, Major—soon Lieutenant Colonel—Royston added as commander of a regiment to the fine reputation he had made as a subaltern and captain.
The despatches of 1901 show that for a great part of that year the 5th and 6th West Australian Mounted Infantry—combined strength in June about 355 men and 380 horses—were in the column of Major General F W Kitchener, who long worked in the Lydenburg district, and generally over the Eastern Transvaal.
In April 1901 General F W Kitchener's column, working from Lydenburg, took part in the operations of Sir Bindon Blood to the north of the Delagoa Railway and in the Middelburg district. During April West Australians were several times engaged, and made some captures of prisoners and stock. On 13th May Major General Kitchener's column crossed to the south of the railway and made for the Ermelo district, to take part in another sweeping movement towards the east under the direction of General Bindon Blood, and back towards the Ermelo-Bethel district. On 15th May there was severe fighting at Grobelaar Recht, in which the 5th had Lieutenant Forrest and Sergeant Ejards and 1 man killed and 5 men wounded, and the 6th 4 men killed and Lieutenant S S Reid and 3 men wounded. On the 16th there was again heavy fighting, in which Lieutenant F W Bell distinguished himself so greatly that he was recommended for and received the Victoria Cross. On 23rd June, at Renshoogte, there was again fighting, when Lieutenant S S Reid and 2 men were killed and 2 severely wounded. During these operations a fair number of prisoners and some carts with ammunition were taken. In July Kitchener's column was back at Middelburg, and after refitting moved north of the railway and had some encounters in which more prisoners were taken. On 16th August 1 man of the 6th was killed, and Lieutenant W H Young of that contingent and 1 man were wounded.
A portion of these contingents were from August to October 1901 with Colonel Benson when he was doing very fine work in the Eastern Transvaal. One of the 6th was wounded in his engagement at Bakenlaagte, 30th October, when Benson was killed (see Scottish Horse).
Towards the close of 1901, and in the early months of 1902, both contingents were acting under General Bruce Hamilton in the Eastern Transvaal, and took part in many of that fine leader's most successful enterprises. They had a few casualties on various occasions. On 1st February 1902 the 5th had 2 men killed at Waterval River, and the 6th had 1 man wounded in the same action; and on the following day Lieutenant G A Morris was killed at Rolspruit. At Roodepoort, on 26th February, Sergeant P J Daly was severely wounded. While with Colonel Wing's column in February and March 1902 the West Australians undertook many arduous marches in the endeavour to get into contact with the enemy, but he had been so often worsted in the Eastern Transvaal, to keep out of sight had become his one desire.