20 January 1879
On 19 and 20 January the British forces under Lord Chelmsford, who had invaded Zululand during the second week of January, established their camp on the slopes of a hill called Isandlwana. The sprawling camp covered an area of half a mile long and 300 yards across, with space for over 250 wagons and carts. 850 white canvas tents were pitched. A deep donga gave protection at the front, while the mountain blocked access on one side and offered high ground for observation. The area offered limited cover for attackers. Owing to the hard ground, consisting mainly of coal-bearing shale, Lord Chelmsford ignored a standing order of the British army that a camp in enemy territory was to be entrenched on all sides. He also neglected to form a protective laager with the wagons. The Zulu army attacked the camp on 22 January.  
References

Mills, G. & Williams, D. (2006). 7 Battles that shaped South Africa, Cape Town: Tafelberg, p. 46.|Potgieter, D.J. et al. (eds) (1970). Standard Encyclopaedia of Southern Africa, Cape Town: NASOU, v. 6, p. 152.