Andries Arnoldus Pienaar was present at the actions at Colesberg, Abrahamskraal and De Wetsdorp. He served as Adjutant to Comdt. W.J. Kolbe of the Bloemfontein Commando.
Kolbe initially held the rank of General. He resigned as such in May 1901 but was subsequently elected Commandant. After the war Kolbe gave Pienaar a short note testifying to his military service. Freely translated it reads: “Panfontein, 14th June 19041, the undersigned', confirm that AA. Pienaar served as my Adjutant and that he was faithful as a Burgher on Commando service. He fell into the hands of the enemy while carrying a despatch, approximately in the month of November 1901, and he cannot be held to blame for the incident. WJ. Kolbe Commedant”. According to the PoW Register Pienaar (PoW No. 26155) was captured at Vierheetslaagte (Smithfield vicinity as per Vorm “B”) on 27 Nov. 1901 and sent to Bermuda.