Henry Mitford Barber, generally known as "Hal", was the younger of the two sons of the eminent naturalist Mary E. Barber* (born Bowker) and her husband, frontier pioneer Frederick W. Barber. In 1869 he moved with his parents to the diamond fields and successfully prospected for diamonds, particularly at Colesberg Koppie. He later joined his brother Frederick M. Barber* ("Freddy") on various hunting expeditions, exploring among others the Waterberg and Soutpansberg (Transvaal) in 1873-1874, and Matabeleland in 1876. Hal was an excellent shot and a keen hunter, but also had a strong interest in natural history. During his travels he collected butterflies and several of the new species he discovered were named after him. His contributions were acknowledged by Roland Trimen* in the preface to his book, South African butterflies... (1887-1889). The two brothers also collected plants and sent some to Kew Gardens.
In February 1884 Hal and Freddy, with their cousin Graham H. Barber travelled to the De Kaap Valley in the eastern Transvaal. They discovered payable gold near present day Barberton and the town established there was named in their honour. When gold was discovered on the Witwatersrand in 1886 Hal accompanied his brother to Johannesburg where they were involved in floating the Ferreira Mining Company. Hal also became a director of the Delagoa Bay Investment Company. In 1894 he married Mary Layard Bowker* and they eventually had four sons. From 1896 he spent several years in the Eastern Cape and then farmed near Potchefstroom from 1906 to 1912. In the latter year he emigrated to Kenya where he became a large scale coffee grower. In 1916 he changed his surname to Mitford-Barberton.
Hal's contribution to archaeology consisted of an article on "The perforated stones of South Africa", which was published in the Journal of the Anthropological Institute of Great Britain and Ireland (Vol. 21, pp. 302-304) in 1892. One of these stones was found in the Kimberley Diamond Mine at a depth of six meters. He also mentions the use of bored stones as bellows-nozzles in working iron among the Bantu speaking population of the eastern Transvaal.