The regiment sailed on the Victorian on 14th February 1900, and arrived at the Cape about 10th March. They joined Lord Roberts at Bloemfontein, and were put into Gordon's, the 3rd Cavalry Brigade, along with the 9th and 16th Lancers. For a sketch of the brigade's work see 9th Lancers.
At Diamond Hill, 11th and 12th June 1900, the 17th were heavily engaged, and lost 2 officers, Major the Honourable L Fortescue and Lieutenant the Honourable C Cavendish, and 4 men killed. From this time onwards their work was quite as arduous as anything the cavalry had done on the way to Pretoria.
Six officers and 7 non-commissioned officers and men were mentioned by Lord Roberts in his final despatch.
In November 1900 the 17th Lancers were formed into a column under Colonel Herbert, which, along with other columns, operated under Colonel Barker in the south-east of the Orange River Colony, taking part in the pursuit of De Wet when he endeavoured to get into Cape Colony in December 1900. The regiment entered Cape Colony in December 1900, and except for two months' operations in the Orange River Colony under Colonel Williams in April and May 1901, the 17th Lancers remained in Cape Colony until the declaration of peace.
In June 1901 the regiment was split up and the squadrons were attached to different columns. These columns had endless very severe marches and some hard fighting. One set of operations resulted in the driving of Kritzinger, with heavy loss, across the Orange River and out of the colony in August 1901. In this affair the 17th Lancers bore an important share. The clearing of the mountainous districts in Cape Colony entailed much hardship and involved great risk, as there was every opportunity for the use of ambuscades.
On 17th September 1901 at Tarkastad a grievous misfortune overtook a squadron under Major Sandeman. The words of Lord Kitchener's despatch of 8th October 1901, para 11, are as follows: "On the 17th September Smuts' commando arrived at Modderfontein, eighteen miles north-west of Tarkastad, where the Boers made a most determined attack upon a squadron of the 17th Lancers, under Major Sandeman, posted to close all egress to the south. The enemy being dressed in khaki were taken for our own troops and got to close quarters, with the advantage of ground, before the mistake was discovered. Thus taken at a great disadvantage, our men offered a most gallant resistance, and worthily maintained the traditions of their regiment. The losses of the squadron were very severe, 3 officers and 20 men being killed, and 2 officers and 30 men wounded. The Boers, who had evidently made the attack in order to elude the close pursuit to which they were subjected, also suffered heavily before the approach of another squadron of the 17th Lancers compelled them to break off the engagement".
The regiment remained split up until after the conclusion of peace. One or other of the squadrons had fighting in almost every part of Cape Colony.
Sergeant T Lawrence gained the Victoria Cross on 7th August 1900 for keeping 12 or 14 Boers at bay while an injured comrade got to safety.
Five officers and 8 non-commissioned officers and men gained mention in Lord Kitchener's despatches during the war, and in the final despatch 3 officers and 4 non-commissioned officers and men were mentioned.