Battle of Groenkop In the Battle of Groenkop ( Battle of Tweefontein ) on 25 December 1901 , Head Commandant Christiaan de Wet ' s Boer commando surprised and defeated a force of Imperial Yeomanry under the command of Major Williams . Background . By late 1901 , de Wet ' s guerilla force based itself near the settlements of Lindley , Bethlehem and Reitz in the northeast part of the Orange Free State . On 28 November , de Wet called a " krijgsraad " ( war council ) of the still - active Boer leaders near Reitz . They determined to strike back at their British tormentors , who numbered 20 , 000 men . As part of Lord Kitchener ' s strategy , the British constructed lines of blockhouses and barbed wire across the veld . The blockhouse lines were designed to restrict the movements of the Boer guerillas so they could be trapped by British mobile columns . One line of blockhouses reached from Harrismith to the Tradoux farm , east of Bethlehem . To protect the construction , Major General Sir Leslie Rundle deployed four dispersed forces . Rundle with 330 men and one gun guarded the wagon road ; the end of the blockhouse line was held by 150 infantry ; a 400 - man regiment of the Imperial Light Horse lay to the east at Elands River Bridge ; Major Williams with 550 men , mostly of the 11th Battalion , Imperial Yeomanry , a 15 - pounder gun and a pom - pom held the high Groenkop . Battle . De Wet carefully scouted the Groenkop position for three days . He noted that the British posted their sentries atop the sheer west side of the kop , instead of at the bottom where they could give timely warning of an attack . The Boer leader determined to scale the west side using the trace of a gully . At 2 : 00 am on Christmas morning , de Wet ' s commando clambered up the steep slope in single file with their boots removed so as to minimise any noise . The surprise was nearly total . Challenged by a single sentry when they were over halfway to the top with a few scattered shots , the Boers , who were ordered into battle by de Wet shouting " Stormt Burgers " swarmed up and over the crest . They began firing downhill into the British tents , inflicting a " massacre . " Savage fighting lasted about 40 minutes before the British gave up . Aftermath . The next morning , one of the 206 British prisoners of the Boers noted that his foes were so short of clothing that some wore women ' s attire . The 250 unwounded British prisoners of war were stripped literally naked before they were turned loose the next day . Kitchener wrote , " It is very sad and depressing that the boers are able to strike such blows , but I fear . . . we shall always be liable to something of the sort from the unchecked rush of desperate men at night . " By 5 February 1902 , Kitchener ' s blockhouse lines were completed and he sent 9 , 000 men on a massive sweep through the countryside . In this first operation , 285 Boers were captured but de Wet and President Marthinus Steyn and their men escaped the trap . The second drive lasted from 16 February to 28 . Again , de Wet got away , but this time he had to abandon most of his cattle . On 27 February , Colonel Henry Rawlinson ' s column encircled and captured a 650 - man Boer commando at Lang Reit , a few miles from Tweefontein . This brought the British " bag " in the successful sweep to 778 surrendered Boers . The third drive by Major Elliott ' s division , from 4 March to 11 March , was a failure , with only about 100 Boers captured . Worse , de Wet escaped to join Fighting General Koos de la Rey in the Western Transvaal .