Both were developed examples of a type associated with the Sotho and Tswana people of present day south-west Botswana and north-west South Africa.
Carved ivory handles are fitted to short steel blades with the sheaths typically made of wood or ivory bound together with braided wire or leather.
Several close examples are pictured in the 1822 volume of Travels in the Interior of Southern Africa by English explorer William Burchell.
The most high-prized of the two measured 9½in (24cm) long and featured a hilt carved as a full-length figure with a stylised design to the torso. Jonathan Riley at Grand Auctions was later told “there is only one other like it in the world in a museum in Los Angeles”.
It sold at £6400 to a buyer from Copenhagen who then bid £2600 for a knife of similar size with an ivory hilt and sheath carved with geometric designs.
The sale took place on July 6.