According to the Muster Roll, Van Rensburg enlisted in the ZAR State Artillery in 1896. He saw Boer War service at Mafeking, Modder River, Donkerhoek (Diamond Hill), Dalmanutha and Belfast prior to being taken PoW at Bosmanshoek. Seeing that on the official PoW Register he was the only one among the 86 Bosmanshoek prisoners designated “Artillerist”, one can speculate that he was involved with the training of a Burgher team to operate the captured British gun. He was sent to St Helena (PoW No 27416) and returned home in September 1902.
In the early 1920’s his address was “Police Barracks, Pretoria.”