29 December 1895
Leander Starr Jameson led a group of about six hundred men of the Mashonaland Mounted Police from Bechuanaland (now Botswana) over the border of the Zuid-Afrikaansche Republiek (also called Republic of Transvaal). The group was under the command of Lt-Col. Henry F. White and bearing small arms, six Maxims and a 12½ pounder field gun. They were heading for Johannesburg in an effort to facilitate a rebellion by Uitlanders - a cosmopolitan group of foreigners who had flocked to the gold fields - and to further the ambition of Cecil John Rhodes for a united South Africa under British rule. Jameson was under the impression that by a sudden advance he would reach Johannesburg before Boer forces could be mobilised to stop him. He was proven wrong and had to surrender to General Cronje on 2 January 1896, leaving seventeen of his men killed, fifty-five wounded and thirty-five missing. Click here to read more on the Jameson Raid.
References

Muller, C.F.J. (ed) (1981). Five Hundred years: a history of South Africa; 3rd rev. ed., Pretoria: Academica, p. 291.|

Potgieter, D.J. et al. (eds) (1970). Standard Encyclopaedia of Southern Africa, Cape Town: NASOU, v. 6, pp. 180-181