The 3rd contingent, two squadrons of Mounted Rifles — frequently called the New Zealand Rough-riders—commanded by Major Jowsey, sailed on 17th February 1900, and were landed at East London. It had been intended that they should go to Beira, but apparently their services were required in the Orange Free State in consequence of the activity of the Boer leaders in the south and east of that country. The contingent was engaged in the operations for the relief of Wepener and the clearing of the country east of the railway. Major Jowsey and his men joined Colonel Pilcher at Kroonstad on 20th May. After the Vaal was crossed there was heavy fighting on the left flank, in which the troops distinguished themselves. On 26th May the New Zealanders, under Robins and Cradock, dashed forward during an engagement, and, passing through some other troops, attacked a ridge and routed a Boer force, killing 5 and taking 7 prisoners. They suffered some casualties.
Before the surrender of Pretoria, French with the 1st and 4th Cavalry Brigades and Hutton with his Mounted Infantry were sent to the north of the capital, and at Waterval released over 3000 prisoners on 6th June: Lord Roberts had entered Pretoria on the 5th. After the enemy had evacuated Pretoria and had retired to the east, French and Hutton worked towards the north-east of the enemy's position, the centre of which, at Pienaars Poort, was of great natural strength. It was necessary to drive back the Boers, and with that object Lord Roberts fought the battle of Diamond Hill, 11th and 12th June 1900. French's cavalry and Hutton's Mounted Infantry—which still included the Canadians, New Zealanders, and Queensland men — were on the British left, and had very heavy fighting in most difficult country. The attempted turning movements were unsuccessful; but by very good work on the part of the infantry and artillery, notably the Sussex Regiment and the 82nd Battery, the enemy's centre was pierced on the 12th and a stiff battle was won.
On the 13th French and Hutton moved east to Doornkraal, but no enemy being found they returned to Kameelfontein, 12 miles north-east of Pretoria. During the next four weeks Hutton's troops, including the New Zealanders, were mainly employed holding posts to the east and south-east of Pretoria — work which entailed great watchfulness, because the enemy was at this time most enterprising. In the despatch of 10th October 1900, para 24, Lord Roberts said: "Hutton, whose outposts were holding the Tigerpoort, Witpoort ridge, east of Irene, was attacked by 2000 Boers with 8 guns at daybreak on 16th July. On this occasion the detachment at Witpoort under Major Munn, 2nd Battalion Royal Irish Fusiliers, consisting of three companies of that regiment and 60 men of the New Zealand MR with two pom-poms, greatly distinguished themselves. By 3 pm the enemy fell back, and at dusk they were in full retreat eastward". The detachment of New Zealanders here mentioned belonged to the 2nd contingent, Lieutenant J Findlay of that corps being severely wounded. On the same day a post held by a party of the 3rd New Zealanders was overwhelmed and captured, Captain J Bourne and Lieutenant J Cameron being taken prisoners.
At this time Lord Roberts was commencing his move from the confines of Pretoria to the eastern boundary of the Transvaal. Hutton's Mounted Infantry Division was split up. He himself, with Alderson's Brigade, which included the Canadians, moved eastward on the south of the Delagoa Railway, while Pilcher's Brigade or corps, which still included the New Zealanders, was put under the command of Mahon and General
Ian Hamilton, who with a strong force marched to the north-east of Pretoria, and thence eastward on the north of the railway. On the 25th July French and Hutton crossed the Wilge River, and Ian Hamilton occupied Balmoral. The enemy retreated in disorder through Middelburg, and Hutton occupied that place on the 27th. During this period the troops had to endure great hardships, the weather being very severe. The New Zealanders had a few casualties.
On 28th July Ian Hamilton, with Mahon's and Pilcher's troops, returned to Pretoria, as operations had to be undertaken west of the capital. On 1st August Hamilton led a fine force towards Rustenburg. The mounted troops, commanded by Mahon, included the Fife Light Horse, Dorset, Devon, and Sussex Yeomanry, Imperial Yeomanry Roughriders, 3rd Regular Mounted Infantry, and the 1st, 2nd, and 3rd New Zealanders. The latter were frequently engaged on this march, and on the 19th lost Lieutenant H Bradburn of the 3rd and one trooper killed, and Captain Hutson of the 2nd and another trooper wounded. After relieving, or at least assisting, Baden - Powell at Rustenburg, Hamilton's force took part in a pursuit of De Wet, which was then in progress, into the Warmbaths district, whence they were recalled to Pretoria, which was reached on 28th August. During the four weeks 400 miles had been covered, and rations for man and horse had been far from plentiful. Colonel Pilcher now left the 3rd Mounted Infantry Brigade for a command in the Orange River Colony.
In August great events had been proceeding in the Eastern Transvaal. On the 15th General Buller, with part of the Natal army, had established touch with French. On the 27th the very strong Boer position at Bergendal had been assaulted, successfully, by Buller's men, and the enemy had been driven to the Lydenburg hills and the Komati Poort district.
On 26th October the New Zealanders, along with 500 other Colonials and four guns RHA, the whole under Colonel Cradock, took part in an expedition into the Schurveberg district, and, after returning to Pretoria, were again sent to the Rustenburg neighbourhood to endeavour to capture Steyn, who, it was thought, was thereabouts. On 20th November the column came back to Pretoria, and on the 22nd marched north-east to join General Paget, who on the 29th fought the very severely contested engagement known as Rhenoster Kop.
On the 28th the enemy had been attacked by General Plumer, and on the morning of the 29th General Paget found a strong force, said to number 4000 men, under General Viljoen, occupying a fine defensive position on a line of kopjes nearly seven miles long. The enemy was well supplied with pompoms and machine-guns. Paget, who was expecting that a force under Colonel Campbell would co-operate from Balmoral, decided to attack without delay. Plumer's two mounted columns were ordered to attack the left of the enemy's positions, Colonel Lloyd with infantry, chiefly West Riding Regiment and Munster Fusiliers, attacking the centre and right. Cradock's column on the extreme left were the first to come into action, and for the next fourteen hours they were under very heavy fire. The West Australians, under Vialls, made a most determined advance over open ground to turn the enemy's right, but eventually they were prevented by the severity of the fire from either advancing or retiring. During the time Vialls was advancing, the 2nd and 3rd New Zealanders, under Captain Crawshaw, were fighting their way, under a terrible fire and over open ground, towards cover that was evidently very strongly held by the enemy. By sheer pluck and determination the New Zealanders managed to get within 300 yards of the position: there they were stopped, and only held their ground by a ceaseless and most accurate fire from a section of the 38th Battery RFA under Lieutenant Craven. The fact that four guns of this battery fired during the day 866 rounds at fairly close range proves the severity of the fighting at Rhenoster Kop. Plumer's other column, under Hickman (see 4th Queensland Mounted Infantry), and Colonel Lloyd's infantry also got to positions almost as near the enemy as the New Zealanders, but nowhere was it found possible to get closer during daylight. By dusk Paget's force had about 100 casualties, including Colonel Lloyd of the West Riding Regiment and 13 men killed, and 10 officers and over 60 non-commissioned officers and men wounded. During the early part of the night desultory fire was kept up on both sides, and all the force, both officers and men, spent the night in digging trenches to make good the ground they had gained: however, in the darkness the Boers silently and quietly melted away. As soon as it was light enough to see, their position was found to be vacated. Signs were neither limited nor indistinct to show that the enemy had lost many killed.
In his telegram of 1st December 1900 Lord Kitchener remarked, "The troops behaved with great gallantry, especially the New Zealand Mounted Rifles, who showed exceptional bravery throughout the day". Out of a total of 6 officers they had 5 wounded—namely, Captain Crawshaw, 2nd contingent; Lieutenants Montgomerie and Somerville, 2nd; Tucker, 3rd; and Surgeon - Captain Godfrey, 3rd. Four non-commissioned officers and men of the New Zealanders were killed and 17 wounded.
Paget's force continued in this neighbourhood throughout December, making almost daily reconnaissances, and being constantly in touch with the enemy. Casualties were frequent. Two Queenslanders were killed one day, and Spencer of the 3rd New Zealand contingent was wounded on the 25th. On the 28th Paget set out on a march towards the north of Rustenburg, 140 miles away, to operate against Beyers. That district was reached on 3rd January 1901, and Paget continued to pursue Beyers' commandos till the 14th, when his force was recalled to Pretoria. This had been a very arduous three weeks, and sickness was rife. After a day or two at Pretoria the force marched to Balmoral, in which neighbourhood the 2nd and 3rd New Zealanders had a good deal of fighting, as on the 23rd, when a patrol of 120 New Zealand and Queensland men under Major Tunbridge was attacked by 400 Boers. The patrol made a fine stand, and drove off the enemy. Captain Crawshaw was again severely wounded, 2 men were killed and 5 wounded. In the despatch of 8th March 1901 Lord Kitchener spoke of the good work done by Paget and Plumer in this district, which tended to facilitate French's great sweep through the Eastern Transvaal.
About 7th February the troops under Paget and Plumer were called off from participation in French's eastern movement, and were railed to Naauwpoort, in Cape Colony, to take part in the operations against De Wet, who was threatening to invade that territory. They left Naauwpoort on the 10th, and were marched up north to intercept De Wet as he crossed the Orange
Paget entrusted Plumer with this expedition. His force consisted of the King's Dragoon Guards (who had just arrived from England) and one squadron of the Carbineers — about 500 men in all; Jeffreys' Corps (late Hickman's), mostly Colonials — some 750 men, with 4 guns and a pom-pom; Cradock's Corps — also about 750 strong. The latter included the New Zealanders. De Wet, with some 3000 men, crossed the river on night of 11th and morning of 12th, and Plumer was in grips with him by noon of the 12th. De Wet's men were in tremendous heart, and quite confident they had nothing to stop them marching straight to the Cape, looting every fat farm they came across on the way. However, from the time Plumer came in contact with them on the 12th he never left them alone for one moment until the 24th, when he—having engaged them almost every day, and having captured all their convoy, their ammunition, and their guns, to say nothing of well on to 200 prisoners — gave over the pursuit of their then disorganised crowd at Hopetown to others. Casualties on Plumer's side were, considering the fighting, very moderate, his chief loss being 24 casualties (including 2 New Zealanders, Heywood and Goldstone) on the day he turned the Boers out of the strong Wolvekuilen position. The Boers suffered much more heavily, and probably had 400 casualties between the 12th and 24th. (See also 4th Victorians).
Plumer was entrained at Hopetown on the 26th for Springfontein, where he again took up the pursuit of De Wet, whose scattered forces had managed to recross the river back into the Orange Colony; but he never succeeded in inducing them to fight an engagement, and by the time he reached Brandfort they had split up and dwindled away to nothing. Plumer halted at Brandfort a day or two and then marched on to Winburg. After a stay of a day or two at this place, Plumer's forces were railed up to Pretoria, and from there commenced the advance on Pietersburg.
The 2nd and 3rd New Zealanders, about 300 warworn veterans, returned home to New Zealand, under the command of Lieutenant Colonel Robin, from the halt at Winburg, sailing on 31st March, and Colonel Cradock was invalided home to England a few weeks later.