The last horse must win, and the Empire had the world on which to draw. Any movement which the Boers would make must be made at once, for already both the cavalry and the mounted infantry were rapidly coming back to their full strength once more. This consideration must have urged Botha to deliver an attack on July 16th, which had some success at first, but was afterwards beaten off with heavy loss to the enemy. The fighting fell principally upon Pole-Carew and Hutton, the corps chiefly engaged being the Royal Irish Fusiliers, the New Zealanders, the Shropshires, and the Canadian Mounted Infantry. The enemy tried repeatedly to assault the position, but were beaten back each time with a loss of nearly a hundred killed and wounded. The British loss was about sixty, and included two gallant young Canadian officers, Borden and Birch, the former being the only son of the minister of militia. So ended the last attempt made by Botha upon the British positions round Pretoria. The end of the war was not yet, but already its futility was abundantly evident. This had become more apparent since the junction of Hamilton and of Buller had cut off the Transvaal army from that of the Free State. Unable to send their prisoners away, and also unable to feed them, the Freestaters were compelled to deliver up in Natal the prisoners whom they had taken at Lindley and Roodeval. These men, a ragged and starving battalion, emerged at Ladysmith, having made their way through Van Reenen's Pass. It is a singular fact that no parole appears on these and similar occasions to have been exacted by the Boers.
Lord Roberts, having remounted a large part of his cavalry, was ready now to advance eastward and give Botha battle. The first town of any consequence along the Delagoa Railway is Middelburg, some seventy miles from the capital. This became the British objective, and the forces of Mahon and Hamilton on the north, of Pole-Carew in the centre, and of French and Hutton to the south, all converged upon it. There was no serious resistance, though the weather was abominable, and on July 27th the town was in the hands of the invaders. From that date until the final advance to the eastward French held this advanced post, while Pole-Carew guarded the railway line. Rumours of trouble in the west had convinced Roberts that it was not yet time to push his advantage to the east, and he recalled Ian Hamilton's force to act for a time upon the other side of the seat of the war. This excellent little army, consisting of Mahon's and Pilcher's mounted infantry, M battery R.H.A., the Elswick battery, two 5-inch and two 4.7 guns, with the Berkshires, the Border Regiment, the Argyle and Sutherlands, and the Scottish Borderers, put in as much hard work in marching and in fighting as any body of troops in the whole campaign.
The renewal of the war in the west had begun some weeks before, but was much accelerated by the transference of De la Rey and his burghers to that side. There is no district in the Transvaal which is better worth fighting for, for it is a fair country side, studded with farmhouses and green with orange-groves, with many clear streams running through it. The first sign of activity appears to have been on July 7th, when a commando with guns appeared upon the hills above Rustenburg. Hanbury Tracy, commandant of Rustenburg, was suddenly confronted with a summons to surrender. He had only 120 men and one gun, but he showed a bold front. Colonel Houldsworth, at the first whisper of danger, had started from Zeerust with a small force of Australian bushmen, and arrived at Rustenburg in time to drive the enemy away in a very spirited action. On the evening of July 8th Baden-Powell took over the command, the garrison being reinforced by Plumer's command.
The Boer commando was still in existence, however, and it was reinforced and reinvigorated by De la Rey's success at Uitval's Nek. On July 18th they began to close in upon Rustenburg again, and a small skirmish took place between them and the Australians. Methuen's division, which had been doing very arduous service in the north of the Free State during the last six weeks, now received orders to proceed into the Transvaal and to pass northwards through the disturbed districts en route for Rustenburg, which appeared to be the storm centre.