During the
Second Boer War (1899–1902) Colenbrander founded and led
Kitchener's Fighting Scouts, a unit fighting for the British. He later commanded a British column. On 9 July 1901 Colenbrander, who then held the rank of
lieutenant-colonel, received the first of numerous
mentions in dispatches, being named by
General Herbert Kitchener for bringing in Boer prisoners during a raid from
Pietersburg in early May. Colenbrander commanded troops that occupied the Boer settlement of
Louis Trichardt on 9 May and on 19 November captured
Warmbaths taking 54 prisoners, 28 wagons and 35 horses, mainly from the
commando of
Christian Frederick Beyers. He remained at Warmbaths to keep the Boer military forces in the area under observation. By December 1901 he held the rank of
colonel. That month, working in conjunction with a column under Lieutenant-Colonel Dawkins he captured Boer Commandant
Adriaan Dirk Badenhorst and 22
burghers. Colenbrander, working independently, then took the towns of
Jericho, capturing 60 prisoners, and
Waterval, killing 5 Boers and taking 29 prisoners in a surprise dawn attack. After the latter he persuaded Chief Linchwe I of the
Kgatla people to stand down a war party of 2,000 warriors who were attempting to recapture livestock taken by Boer General
Jan Kemp. Colenbrander was concerned that Linchwe's men posed a threat to Boer women and children. In February 1902 Colenbrander's column was ordered south, which allowed Beyers to raid Pietersburg. Afterwards Colenbrander was ordered to
Rustenburg to search for Beyers. Beyers besieged Fort Edward near Louis Trichardt and it was almost forced to surrender, its water supply being cut off. Colenbrander learnt of the attack and moved from
Krugersdorp to launch a surprise dawn attack on the besiegers on 29 March, driving them off with three dead and four taken prisoner. Colenbrander afterwards followed Beyers to
Pylkop. On 8 April he launched a successful attack on Beyers' position at
Malipspoort. Although a planned encirclement failed to prevent the escape of the Boer force Colenbrander captured the town, much equipment and 119 prisoners, having inflicted nine dead. In pursuing Beyers to
Oud Agatha, part of Colenbrander's force was ambushed and it lost six dead, 12 wounded and 30 captured. After this Beyers' force dispersed and Colenbrander returned to Pietersburg. In May 1902 Colenbrander carried out operations in the
Malip Valley, killing one Boer, wounding 21 and capturing 101 before Beyers' arrival for peace negotiations ended operations. Colenbrander was appointed a
Companion of the Order of the Bath on 26 June 1902 for his war service. After the war's end Colenbrander agreed to purchase from the British Army around 11,000 surplus horses, for a total in excess of £80,000 (). Three thousand of the horses died and Colenbrander was unable to pay £30,000 () of the contracted price and was forced to declare bankruptcy. == Later life ==