On the same day another cavalry regiment was in trouble. Onderste Poort, a few miles north of Pretoria, was attacked by Grobler of Waterberg, and while reinforcements were on their way he drove back still nearer to the capital the force which was holding the outpost, and forced one troop to surrender.
The situation was alarming. The districts west and south-west of the capital were infested by energetic commandos which had thwarted all Baden-Powell's and Smith-Dorrien's efforts to suppress them, and Grobler was threatening Pretoria from the north. There were indications that the enemy's plan was to transfer the opposition from the east to the west; and if so, then Lord Roberts' force, whose front after Diamond Hill faced eastwards, would have to conform to the movement. A few weeks previously it had been weakened by the departure of Hunter's strong column for the Free State, and now Lord Roberts was compelled to redress the balance by calling up Methuen's Division from Lindley to Krugersdorp, where it arrived on July 18. French was ordered to operate north of Pretoria with cavalry, and a column under Ian Hamilton[49] was also sent up.
Methuen marched at once on Rustenburg, and cleared Olifant's Nek on July 21. The scheme of shutting up the Boers in it failed, as Baden-Powell was unable to close the northern exit, and they escaped with slight loss.
At the beginning of August the situation was, if anything, worse. The events which succeeded the occupation of Bloemfontein were repeating themselves in the Western Transvaal. Methuen had been recalled from the Rustenburg expedition to deal with an outbreak on the line from Johannesburg to Klerksdorp, which fell into the hands of the enemy; 5,000 Boers were reported to be on or near the Magaliesberg; a small British force was besieged in Brakfontein, west of Rustenburg, on the road to Mafeking; De Wet was at large in the Free State, and it seemed probable that he would come up into the Transvaal and add to the trouble.
At the end of July Ian Hamilton's force was diverted from its movement towards the north and ordered westward to relieve and bring away Baden-Powell; and Carrington was instructed to co-operate from Mafeking. Lord Roberts had decided to abandon Rustenburg and Olifant's Nek and the greater part of the Magaliesberg. These detached positions detained more troops than he could spare[50] and were difficult to supply. Ian Hamilton's trek lasted only a few days. He recaptured Zilikat's Nek, and on August 5 brought away Baden-Powell, who left Rustenburg most unwillingly and who was ready to sustain another siege in it. Lord Roberts, however, would not heed his repeated protests, and the only section of the Magaliesberg held after the withdrawal from Rustenburg was that lying between Pretoria and Zilikat's and Commando Neks. Rustenburg and Olifant's Nek had called for the diversion of three columns in succession: Smith-Dorrien's, which did not reach them, and then Methuen's and Ian Hamilton's; and the abandonment of them was imperative. From the west Carrington made an attempt to relieve Brakfontein on August 5, but was compelled by the presence of the enemy in superior force to return to Mafeking. The relief was effected ten days later, not from the west, but by Lord Kitchener with a column that had been engaged in the pursuit of De Wet.
Suddenly all the operations were deranged by the news that De Wet had crossed the Vaal at Schoeman's Drift on August 6, and the greater part of the British Army in the Transvaal was either directly or indirectly turned on to the pursuit of one man; Lord Kitchener, as usual when energy and pushing power rather than tactical skill were looked for, being placed in general charge of the operations. The two most determined and unfaltering men in South Africa were now pitted against one another.
De Wet's escape from the Brandwater Basin on July 15 was soon discovered and he was unable to get a good start. Broadwood's and Little's mounted brigades were sent after him, now and then taking long shots at him or worrying his rearguard. His object was to conduct Steyn and the Free State Government officials into the Transvaal, where they could co-operate with Kruger. He chose the route which appeared to him, and rightly so, to be the line of least resistance, namely, towards the Vaal Drifts near Potchefstroom; instead of making for the upper reaches of the river, on the other side of which Buller was established on the Natal railway.
It was soon found impossible to overtake him, even with mounted troops. The only course was to shepherd him into a fold from which he could not escape. The tracery on the map of his movements and of those of his chief scout Theron, intersected by the reticulations of the pursuing columns, resembles a spider's web in disorder.
Finally he was hemmed in on the left bank of the Vaal near Reitzburg. On the right bank Methuen, supported by Smith-Dorrien, was watching the drifts. He did his best, but his force was insufficient for the purpose, and on August 6 De Wet, with it is said no less than 400 wagons, entered the Transvaal at Schoeman's Drift, the greater part of Methuen's force having been sent to hold a drift lower down. Methuen doubled back and fell upon the Boer rearguard, which, though driven out of successive positions, maintained itself long enough to allow the main body to escape unscathed.