At the outbreak of the Anglo-Boer War, the Boer forces identified diamond-rich Kimberley as an important strategic base and quickly besieged the city, trapping its residents, including Cecil Rhodes, inside. In response, the British deployed an army under Lord Methuen to relieve the city. The size of the army and lack of knowledge of the terrain compelled them to advance from the coast along the line of the railway so that a supply of troops, water, food and equipment could be ensured.
Methuen first encountered Boer forces at Belmont; this was followed by further battles at Graspan and the Modder River, from which the Boers made a tactical withdrawal to Magersfontein, a range of hills 30km south of Kimberley. Here the Boer generals, under the leadership of General Cronjé and the tactical direction of Koos de la Rey, decided to dig a line of trenches along the bottom of the koppie rather than defend the top of the ridge of hills, as was their usual tactic.
In the early hours of December 11, 1899, the British advanced on Magersfontein, fully expecting the enemy to be lined along the ridge. The British were led by the Highland Regiment, fresh from campaigns in North Africa and India, and considered the elite of the British army. Just before dawn, as they fanned out into attack formation, four thousand Boers in the trenches just a few hundred metres away opened fire. The use of trenches was, at that point, a rare tactic in modern warfare, and the element of surprise caused devastation in the ranks. Those not killed or wounded in the first volleys were pinned down by snipers for the rest of the day, unable to move in the coverless veld and suffering appallingly under the hot sun. The next day the British withdrew to the Modder River, and the relief of Kimberley was delayed for two months. The defeat was one in a series of three the British suffered within what became known as “Black Week”, news of which sent shock waves through the British public who had been expecting their forces to overrun the “crude farmers” before Christmas.