The British commander-in-chief in South Africa, General Sir Redvers Buller initially planned to march with a single large force on the Boer capitals of Bloemfontein and Pretoria. However public opinion demanded relief of the sieges of Kimberley, Ladysmith and Mafeking — pressure that was attributable in part to Rhodes's presence in Kimberley and lobbying in London. Buller therefore had to change his plans and divide his forces: Lord Methuen was sent north by the War Office in December 1899 with the objective of relieving Kimberley and Mafeking, while Buller himself went to Natal. On 1 December 1899, communications were established between Methuen's relief column and the defenders in the town. However, Methuen's advance ground to a halt after the Boers inflicted heavy casualties on his force at the Battle of Modder River and defeated him resoundingly at the Battle of Magersfontein. These, and other defeats elsewhere, came to be called "Black Week" by the British. Thus, for two of the four months of the siege, the 10,000 British troops at Modder River who were within of the town, were unable to reach it.