This corps was a portion of the second contingent of the Colony of New South Wales, the remainder of the contingent being Mounted Infantry.
The 1st Australian Horse sailed from Newcastle and Port Jackson on 14th November 1899 and 17th January 1900, both detachments being taken to Cape Colony. On their arrival the first detachment was sent to General Sir J P D French, who was then operating in the Colesberg district, and during part of December 1899 and January 1900 the corps did much good work, and constantly saw hard fighting. On 16th January a patrol, made up of New South Wales Lancers and a few Australian Horse, was cut off, and in the endeavour to break through, Lieutenant W V Dowling of this corps was wounded and captured, and Sergeant Major Griffin, also of this corps, and Corporal Kirkpatrick of the Lancers, were killed. Lieutenant Dowling was found by Lord Roberts' troops in Bloemfontein when they entered that town on 13th March.
The squadron, as part of Colonel Porter's Brigade, accompanied General French to Modder River, and took part in the operations for the relief of Kimberley and in the advance of Lord Roberts' army to Bloemfontein. (See NSW Lancers). The squadron had casualties at Poplar Grove and Driefontein.
When the 1st Australian Horse marched into Bloemfontein on 13th March their strength was 5 officers, 112 men, and 101 horses. They were now sent to the Glen position north of the town, where much heavy patrol work fell to them. On the 20th they lost 1 man killed and 8 wounded.
In March 1900 the squadron was attached permanently to the Royal Scots Greys, and with that distinguished regiment fought at the battle of Karee Siding, 29th March; in several engagements southeast of Bloemfontein in April; in the advance to Pretoria, 3rd May to 6th June; and east of Pretoria in June, July, August, and September.
On 10th May, the day on which Lord Roberts crossed the Zand River, Lieutenant Wilkinson was, with some of the 6th Dragoons and Royal Scots Greys, fired on when approaching a kraal where a white flag was flying. The officer in command, Captain Elworthy, and several men were killed and others wounded, and Lieutenant Wilkinson and several men were taken prisoners. On this same day the squadron and two squadrons of the Greys had very heavy fighting. They had been pushed forward to seize a hill, and the enemy being in great force all round, they were wellnigh cut off. The hill had temporarily to be vacated, but on reinforcements and guns coming up the Boers retired. Throughout the advance to Pretoria, particularly in the last days of May, after the Vaal was crossed, Porter's Brigade had frequently very heavy fighting, and progress was only made by all ranks showing great determination.
Along with the New South Wales Lancers the corps had the good fortune to be part of the force which released the prisoners at Waterval, north of Pretoria, on 6th June. This was not effected without difficulty. A strong force of Boers appeared as our troops were retiring; indeed the bulk of the brigade were far on their way, and the rearguard, about 400 strong, were pressed by 2000 of the enemy with artillery. Lieutenant Colonel Yardley of the Inniskillings in their War Record, p 101, praised the men of his own regiment, the New South Wales Lancers, the Scots Greys, and 1st Australian Horse. He said: "I was much indebted to a small party of the Australian Horse who, at my request, remained to help hold an advanced post which, save for the shelter of a stone wall would not have been possible".
Along with the New South Wales Lancers the 1st Australian Horse were present under General French, in Porter's Brigade, on the extreme left, at Diamond Hill, on 11th and 12th June 1900. The brigade was strongly opposed in difficult country, and was unable to carry out a turning movement. So great had been the loss of horses that the squadron had only 2 officers and 8 men mounted in this battle.
The corps took part in the advance from Pretoria to the Portuguese border. On 24th July Captain Ebsworth was killed—strangely enough, almost the only casualty in the army that day. "While standing by his horse and spying the enemy through his glass, a chance bullet, fired quite 2000 yards off, struck the glass and penetrated his brain". General French's further operations have been touched upon under the Imperial Light Horse and under the New South Wales Lancers. Part of the corps sailed for home in November 1900; the remainder continued to do good work down to March 1901. On the 31st of that month Captain Wilkinson and 32, all ranks, the remnant of the corps, sailed for home.