Second Boer War
First British relief attempts

On 31 October 1899, General Sir Redvers Henry Buller, a much-respected commander, arrived in South Africa with the Army Corps, made up of the 1st, 2nd and 3rd divisions. Buller originally intended an offensive straight up the railway line leading from Cape Town through Bloemfontein to Pretoria. Finding on arrival that the British troops already in South Africa were under siege, he split his army corps into detachments to relieve the besieged garrisons. One division, led by Lieutenant General Lord Methuen, was to follow the Western Railway to the north and relieve Kimberley and Mafeking. A smaller force of about 3,000, led by Major General William Gatacre, was to push north towards the railway junction at Stormberg and secure the Cape Midlands District from Boer raids and local rebellions by Boer inhabitants. Buller led the major part of the army corps to relieve Ladysmith to the east.

The initial results of this offensive were mixed, with Methuen winning several bloody skirmishes in the Battle of Belmont on 23 November, the Battle of Graspan on 25 November, and at a larger engagement, the Battle of Modder River, on 28 November resulting in British losses of 71 dead and over 400 wounded. British commanders had been trained on the lessons of the Crimean War and were adept at battalion and regimental set pieces, with columns manoeuvring in jungles, deserts and mountainous regions. What British generals failed to comprehend was the impact of destructive fire from trench positions and the mobility of cavalry raids. The British troops went to war with what would prove to be antiquated tactics—and in some cases antiquated weapons—against the mobile Boer forces with the destructive fire of their modern Mausers, the latest Krupp field guns and their novel tactics.

The middle of December was disastrous for the British Army. In a period known as Black Week (10–15 December 1899), the British suffered defeats on each of the three fronts. On 10 December, General Gatacre tried to recapture Stormberg railway junction about 80 kilometres (50 mi) south of the Orange River. Gatacre's attack was marked by administrative and tactical blunders and the Battle of Stormberg ended in a British defeat, with 135 killed and wounded and two guns and over 600 troops captured.

At the Battle of Magersfontein on 11 December, Methuen's 14,000 British troops attempted to capture a Boer position in a dawn attack to relieve Kimberley. This too turned into a disaster when the Highland Brigade became pinned down by accurate Boer fire. After suffering from intense heat and thirst for nine hours, they eventually broke in ill-disciplined retreat. The Boer commanders, Koos de la Rey and Cronjé, had ordered trenches to be dug in an unconventional place to fool the British and to give their riflemen a greater firing range. The plan worked, and this tactic helped to write the doctrine of the supremacy of the defensive position, using modern small arms and trench fortifications. The British lost 120 killed and 690 wounded and were prevented from relieving Kimberley and Mafeking. A British soldier said of the defeat:

Such was the day for our regiment Dread the revenge we will take. Dearly we paid for the blunder – A drawing-room General's mistake. Why weren't we told of the trenches? Why weren't we told of the wire? Why were we marched up in column, May Tommy Atkins enquire...

The nadir of Black Week was the Battle of Colenso on 15 December, where 21,000 British troops, commanded by Buller, attempted to cross the Tugela River to relieve Ladysmith, where 8,000 Transvaal Boers under the command of Louis Botha were waiting for them. Through a combination of artillery and accurate rifle fire and better use of the ground, the Boers repelled all British attempts to cross the river. After his first attacks failed, Buller broke off the battle and ordered a retreat, abandoning many wounded men, several isolated units and ten field guns to be captured by Botha's men. Buller's forces lost 145 men killed and 1,200 missing or wounded and the Boers suffered only 40 casualties, including 8 killed.
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