Lord Roberts had now been six weeks in the capital, and British troops had overrun the greater part of the south and west of the Transvaal, but in spite of this there was continued Boer resistance, which flared suddenly up in places which had been nominally pacified and disarmed. It was found, as has often been shown in history, that it is easier to defeat a republican army than to conquer it. From Klerksdorp, from Ventersdorp, from Rustenburg, came news of risings against the newly imposed British authority. The concealed Mauser and the bandolier were dug up once more from the trampled corner of the cattle kraal, and the farmer was a warrior once again. Vague news of the exploits of De Wet stimulated the fighting burghers and shamed those who had submitted. A letter was intercepted from the guerilla chief to Cronje's son, who had surrendered near Rustenburg. De Wet stated that he had gained two great victories and had fifteen hundred captured rifles with which to replace those which the burghers had given up. Not only were the outlying districts in a state of revolt, but even round Pretoria the Boers were inclined to take the offensive, while both that town and Johannesburg were filled with malcontents who were ready to fly to their arms once more.

Already at the end of June there were signs that the Boers realised how helpless Lord Roberts was until his remounts should arrive. The mosquitoes buzzed round the crippled lion. On June 29th there was an attack upon Springs near Johannesburg, which was easily beaten off by the Canadians. Early in July some of the cavalry and mounted infantry patrols were snapped up in the neighbourhood of the capital. Lord Roberts gave orders accordingly that Hutton and Mahon should sweep the Boers back upon his right, and push them as far as Bronkhorst Spruit. This was done on July 6th and 7th, the British advance meeting with considerable resistance from artillery as well as rifles. By this movement the pressure upon the right was relieved, which might have created a dangerous unrest in Johannesburg, and it was done at the moderate cost of thirty-four killed and wounded, half of whom belonged to the Imperial Light Horse. This famous corps, which had come across with Mahon from the relief of Mafeking, had, a few days before, ridden with mixed feelings through the streets of Johannesburg and past, in many instances, the deserted houses which had once been their homes. Many weary months were to pass before the survivors might occupy them. On July 9th the Boers again attacked, but were again pushed back to the eastward.

It is probable that all these demonstrations of the enemy upon the right of Lord Roberts's extended position were really feints in order to cover the far-reaching plans which Botha had in his mind. The disposition of the Boer forces at this time appears to have been as follows: Botha with his army occupied a position along Delagoa railway line, further east than Diamond Hill, whence he detached the bodies which attacked Hutton upon the extreme right of the British position to the south-east of Pretoria. To the north of Pretoria a second force was acting under Grobler, while a third under De la Rey had been despatched secretly across to the left wing of the British, north-west of Pretoria. While Botha engaged the attention of Lord Roberts by energetic demonstrations on his right, Grobler and De la Rey were to make a sudden attack upon his centre and his left, each point being twelve or fifteen miles from the other. It was well devised and very well carried out; but the inherent defect of it was that, when subdivided in this way, the Boer force was no longer strong enough to gain more than a mere success of outposts.

De la Rey's attack was delivered at break of day on July 11th at Uitval's Nek, a post some eighteen miles west of the capital. This position could not be said to be part of Lord Roberts's line, but rather to be a link to connect his army with Rustenburg. It was weakly held by three companies of the Lincolns with two others in support, one squadron of the Scots Greys, and two guns of O battery R.H.A. The attack came with the first grey light of dawn, and for many hours the small garrison bore up against a deadly fire, waiting for the help which never came. All day they held their assailants at bay, and it was not until evening that their ammunition ran short and they were forced to surrender. Nothing could have been better than the behaviour of the men, both infantry, cavalry, and gunners, but their position was a hopeless one. The casualties amounted to eighty killed and wounded. Nearly two hundred were made prisoners and the two guns were taken.

On the same day that De la Rey made his coup at Uitval's Nek, Grobler had shown his presence on the north side of the town by treating very roughly a couple of squadrons of the 7th Dragoon Guards which had attacked him. By the help of a section of the ubiquitous O battery and of the 14th Hussars, Colonel Lowe was able to disengage his cavalry from the trap into which they had fallen, but it was at the cost of between thirty and forty officers and men killed, wounded, or taken. The old 'Black Horse' sustained their historical reputation, and fought their way bravely out of an almost desperate situation, where they were exposed to the fire of a thousand riflemen and four guns.