Black Week saw the British in South Africa suffer three serious defeats in six days. The first came at Stormberg (10 December), where an army under Sir William Gatacre suffered a defeat after a badly handled night march. Next came Magersfontein (11 December). This saw the defeat of an expedition under Lord Methuen that had been attempting to relieve Kimberley. Finally, on 15 December the commander in chief in South Africa, Sir Redvers Buller, led his army to defeat at Colenso, ending his first attempt to relieve the siege of Ladysmith.
This was the worst run of defeats suffered by the British army since the Napoleonic wars. All three battles saw the British suffer significantly heavier losses than the Boers (Colenso was probably the worst in this respect – the British suffered 1137 casualties while inflicting only 38). What made it particularly embarrassing was the poor performance of the British generals at each of these battles. Methuen and Buller tried simple frontal assaults and then lost control of their battles, while Gatacre managed to first get lost, then fail to realise that he had left over 600 men behind.
The reaction in Britain took two strands. First was a feeling of gloom and embarrassment. The embarrassment was particularly acute for any Briton living overseas. The armies defeated in South Africa had contained some of the most famous regiments in the British army – the Black Watch had been at Magersfontein, a brigade of the Fusiliers at Colenso. For such famous regiments to suffer three humiliating defeats at the hands of a small number of Boer farmers was inexplicable. Many of Britain’s enemies took heart at the poor performance of the army.
The second strand of public reaction was enthusiasm for the war. Tens of thousands of men tried to volunteer, and on 18 December the government relented, allowing twelve battalions of militia and 20,000 members of the yeomanry to go to South Africa. Amongst the units formed at this time was the City of London Imperial Volunteers, a unit of 1,550 men raised in under two months. A similar wave of enthusiasm swept Australia, New Zealand and Canada.
The most high profile casualty of Black Week was Sir Redvers Buller. In the aftermath of Colenso he had written to General White, commanding the garrison of Ladysmith, suggesting that he should surrender to the Boers. This message caused great concern in London. On 17 December Field Marshal Lord Roberts was appointed to take command in South Africa, with Lord Kitchener as his chief of staff. Buller was kept on in a more junior capacity, as despite the disaster at Colenso his personal popularity was still high.
Ironically Black Week had little impact on the fighting in South Africa. Kimberley and Ladysmith remained in British hands. The Boers who had invaded north east Cape Colony around Stormberg stayed put. The arrival of Lord Roberts would see the British performance improve markedly, although there were still military defeats to endure before the traditional military stage of the war was finished.