Sir Henry Bartle Frere, the British High Commissioner in Southern Africa, deliberately contrived a war with the Zulu king Cetshwayo, to further his scheme for the creation of a South African Confederation. Acting without approval, and therefore desperate to present the government with a fait accompli, the invasion force commanded by Lord Chelmsford marched into Zululand at the height of the rainy season. Setting camp at Isandlwana, Chelmsford sent half his force in pursuit of a decoy band of Zulu impi (warriors). The main Zulu army outmanoeuvred Chelmsford and descended on the remaining 1,800 soldiers at the British base under Colonel Durnford. The full Zulu ‘bull’s-horns’ formation charge of 20,000 warriors swiftly overran the British rocket battery, then turned their right-flank. Contained for an hour by repeated volleys from Martini-Henry rifles, repeated assaults overwhelmed the British positions, most of whom would be annihilated in brutal hand-to-hand fighting.