8 June 1900
General Sir Redvers Buller' forces attacked Botha's Pass in Natal. After a five hour battle the Republican forces were in retreat, defeated. His troops relieved British forces at Ladysmith in Natal on 28 February, 1900.  The British forces had been under siege by the Boers since 2 November 1899. A key position, Van Wyk's Kop, was too lightly armed to resist the South African Light Horse brigade. General Buller was now free to enter the Orange Free State. The attack by General Buller occurred amid the South African War II, also known as the Second Anglo-Boer War which broke out on 9 October 1899.
References

Boddy –Evans, A. ‘This Day n African History: 8 June’, from About African History, [online], Available at https://africanhistory.about.com [Accessed: 15 May 2013]|South African History Online, ‘General Sir Redvers Henry Buller's troops relieve British forces at Ladysmith’, [online], Available at www.sahistory.org.za [Accessed: 15 May 2013]