18 December 1899
The appointment of Lord Roberts as Supreme Commander of the British forces in South Africa came after a series of failed campaigns against Boer Commandos in the South African War (Second Anglo-Boer War). The Commandos mounted pre-emptive strikes against British garrisons in Mafikeng, Kimberley and Ladysmith. They also scored some morale boosting victories in Colenso, Magersfontein and Spionskop. And in one of these campaigns, Lord Robert's only son was killed in action. The Colonial Office sent massive troop reinforcements under the command of General Sir Redvers Henry Buller, a respected commander. Buller attempted to relieve the besieged garrisons, but initial attempts failed. The British were using war tactics reminiscent of the Crimean War in a terrain that was completely different. They were also faced with Boer Commandos armed with German Mausers, something the British did not expect. The failure of these campaigns led the Colonial Office to appointing Lord Roberts as Supreme Commander and sent him to South Africa. Roberts, accompanied by Lord Kitchener, arrived in South Africa early in 1900. With greatly increased troop numbers, Roberts set about to turn the tide around and ensure British victory at all costs. The Foreign Office had shown extreme anxiety at the way the war had been going. To ensure Roberts succeeded, he was backed by a force consisting of 180 000 soldiers and had enourmaous resources at his disposal. With this the British showed the determination to turn the war around. Roberts immediately set about relieving British garrisons in the Cape and Natal. This was achieved in the first few months of 1900. Mafikeng and Ladysmith were relieved and the Boer Commandos were driven out. Roberts then turned North and entered the Transvaal Republic. By the end of June Pretoria had been captured and the Commandos were all but defeated. With his mission accomplished in South Africa, Roberts handed over command of the British forces in South Africa and returned to England.
References

Giliomee, H and Mbenga, B. (eds) (2007) New History of South Africa (Cape Town), p. 214|Pakenham, T (1979). The Boer War. (New York)