Paul Kruger, the President of the South African Republic, issued an ultimatum on 9 October 1899, giving the British government 48 hours to withdraw all their troops from the borders of both the Transvaal and the Orange Free State, albeit Kruger had ordered Commandos to the Natal border in early September and Britain only had troops in garrison towns far from the border, failing which the Transvaal, allied to the Orange Free State, would declare war on the British government.
War was declared on 11 October 1899 with a Boer offensive into the British-held Natal and Cape Colony areas. The Boers had about 33,000 soldiers, and decisively outnumbered the British, who could move only 13,000 troops to the front line.
Meanwhile, to the north-west at Mafeking, on the border with Transvaal, Colonel Robert Baden-Powell had raised two regiments of local forces amounting to about 1,200 men in order to attack and create diversions if things further south went amiss. Mafeking, being a railway junction, provided good supply facilities and was the obvious place for Baden-Powell to fortify in readiness for such attacks. However, instead of being the aggressor Baden-Powell and Mafeking were forced to defend when 6,000 Boer, commanded by Piet Cronjé, attempted a determined assault on the town. But this quickly subsided into a desultory affair with the Boers prepared to starve the stronghold into submission, and so, on 13 October, began the 217-day Siege of Mafeking.
Lastly, over 360 kilometres (220 mi) to the south of Mafeking lay the diamond mining city of Kimberley, which was also subjected to a siege. Although not militarily significant, it nonetheless represented an enclave of British imperialism on the borders of the Orange Free State and was hence an important Boer objective. The Siege of Kimberley took place during the Second Boer War at Kimberley, Cape Colony (present-day South Africa), when Boer forces from the Orange Free State and the Transvaal besieged the diamond mining town. The Boers moved quickly to try to capture the area when war broke out between the British and the two Boer republics in October 1899.
Boer guns began shelling the British camp from the summit of Talana Hill at dawn on 20 October. Penn Symons immediately counter-attacked: his infantry drove the Boers from the hill, for the loss of 446 British casualties, including Penn Symons.
The Battle of Elandslaagte was a battle of the Second Boer War, and one of the few clear-cut tactical victories won by the British during the conflict. However, the British force retreated afterward, throwing away their advantage.