Mafeking as well as Kimberley were now in the hands of Lord Roberts, but the Western line joining them to Capetown was not yet secure.  The districts of Cape Colony west of De Aar and Hopetown were remote and backward, and sparsely inhabited by discontented and unprosperous Dutch farmers.  Nearly a year before, while the Cape Government was placidly blinking under the shadow of Table Mountain and only taking action that thwarted the attempts of the Imperial Government to prepare for war, and like the unjust steward intriguing for reception in Boer houses if the Empire should fail, arms had been sent into these districts by the Boers of the Republics, and courses of instruction in the use of them were actually being held.

To stir up the discontented and set the veld on fire, a party of Transvaalers swooped down from Vryburg before the war was many days old.  Rebel commandos were raised, and most of the districts lying between the Orange and the Molopo were involved, some of them being annexed by proclamation to the Republics.  For several months the trouble was confined to the right bank of the Orange, but during February it passed over to the left bank.

In pursuance of his policy of striking swiftly and strongly at the centres of population, and not from neglect, Lord Roberts had left the rebellious and disaffected districts more or less to themselves, in the belief that indirect action would retrieve the situation and that his advance would take the heart out of the rebels and deter them from crossing the river; and for some months there had been no British troops south of the Orange except at De Aar and Hopetown.

Now, however, the railway, which until his arrival at Bloemfontein was his only line of communication, was threatened.  The Prieska and Herbert districts on the left bank of the Orange, and even the remote Gordonia district lying in the angle between the Orange and the Molopo, which was too far away to be included in the first batch of proclamations, were annexed by the Boers.  There was much danger of the advancing army not only finding its communications broken, but also a formidable rebellion springing up behind it.

The troops on the line were insufficient to deal with the situation, and Lord Roberts was obliged to draw upon Clements, who was acting in the other disturbed districts of the Cape Colony south of the Free State.  Lord Kitchener, who chanced to be passing through De Aar on his way back from Naauwpoort, where he had been sent to look after the central advance, made arrangements for the Prieska operations and rejoined Lord Roberts at Kimberley; but his presence was soon required again at De Aar.  Three columns had started westward from the line, but the centre column, which was composed of the troops withdrawn from Clement’s command, met with opposition in the Prieska district, and was compelled to retire on March 6.  When the news reached Lord Roberts he sent Kitchener to take charge of the operations, which from that time was successful.  The rebellion south of the Orange was suppressed; the leaders disappeared; and by the end of the month Kitchener was free to return to Head Quarters at Bloemfontein.