Spion Kop, just northeast of Warren's force, was the largest hill in the region, being over in height (relative height from its base). It lay almost exactly at the centre of the Boer line. If the British could capture this position and bring artillery to the hill then they would command the flanks of the surrounding Boer positions. On the night of 23 January, Warren sent the larger part of his force under Major General Edward Woodgate to secure Spion Kop. Lieutenant Colonel Alexander Thorneycroft was selected to lead the initial assault. (Thorneycroft was one of six special service officers, among whom were also Robert Baden-Powell and Herbert Plumer, despatched to South Africa shortly before the war to recruit local irregular corps. Thorneycroft's mounted infantry were raised in Natal and numbered 360.)