Robert Henry Dingley came to the Cape Colony from England during 1812-1813 and received his commission as an ensign in the Cape (Hottentot) Regiment on 8 June 1814. His regiment was deployed to the eastern frontier of the colony, an area disputed by the Xhosa and colonial farmers during the Fourth and Fifth Frontier Wars (1811-1812 and 1818-1819). He made a number of sketches which provide an early first-hand record of the inhabitants and some features of the frontier region, twenty of which are now in the Africana Museum in Johannesburg. One of these, made in October 1815, was an excellent painting of two fresh water fishes from the Koonap River, a tributary of the Great Fish River. The fishes were the Eastern Cape rocky, Sandelia bainsii (which he called a carper), first described by Count F. de Castlenau* in 1861; and the Moggel, Labeo umbratus (which he called a whitefish), first described by Andrew Smith* in 1841. The painting predates all other records of freshwater fishes from the Eastern Cape.
Dingley was placed on half pay when his regiment was disbanded in December 1817. He and his wife returned to Cape Town from Algoa Bay on 21 October 1818 and left for England.