17 May 1900
The Siege of Mafeking (now known as Mafikeng) was an important battle in the South African War (Second Anglo-Boer War). The war began in late 1899; President Kruger issued an ultimatum, instructing the British to withdraw their soldiers from the border of the Transvaal. When the British failed to heed the instruction, Kruger's government declared war. In 1900 Afrikaans Commandant Eloff was sent to put the town of Mafikeng under siege. Eloff instructed General Piet Cronje to lead approximately 5000 Afrikaner soldiers (numbers vary) to Mafikeng. For almost seven months fighting ensued; with the Afrikaner soldiers burning the Barolong huts and the defences that the British lieutenant-general, Robert Baden-Powel, had set up. A turning point occurred on 17 May 1900, when British forces, led by Colonel Mahon and Lord Roberts fought their way into the city and lifted the siege. The British forces were dubbed "defenders of Mafeking". The relief is said to have sparked so much jubilation in London that a new word was coined in English, (to "maffick" came to mean "to revel inordinately). Although the war was fought primarily between the British and the Afrikaner soldiers, the battle of Mafeking claimed the lives of 400 Barolong, who fought alongside the British. The British lost were 212 soldiers and over 1000 Afrikaner lives were lost.
References

Think quest. (1999). Overview of the siege. [Online]. Available at:  https://library.thinkquest.org. [Accessed 11 May 2010]|Times Archive. (1985) The siege of Mafeking. [Online]. Available at: www.timesonline.co.uk. [Accessed 11 May 2010]|North West Province. (1997) The Onset of the Anglo Boer War South African War [Online]. Available at www.tourismnorthwest.co.za.[Accessed 11 May 2010]| History Today. (1900) The Relief of Mafeking. [Online] Available at: www.historytoday.com. [Accessed 11 May 2010]