Johannes Jacobus Pienaar was a grandson of the old Free state Commandant with the same name.
He was born in Ladybrand on 16 April 1877 and went with his parents to the Transvaal when he was still very young.
When his family went back to Ladybrand in 1894 he stayed behind and start working as a official at the post office.
When the Witwatersrand was divided in Veldcornet units he workes as a clerq at the central unit.
When the war started he was appointed as assistant veldcornet and joined a section under General Schoeman at Coleberg.
He was promoted to Veldcornet and joined General Lemmer’s commando. He was part of the battle at Rensburg siding and was wounded here.He also fought in the battles of Donkerhoek, Dalmanutha, Witpoort, Helvetia, Belfast, Vaalkop and a few more. He was again wounded a few times and became a commandant at the end of the war