He was born in Swellendam, the third son (of six) of Jacobus Johannes Uys (nicknamed Koos Bybel (Bible) because of his religious beliefs).
Ia lahir di Swellendam, dan putra ketiga (dari enam bersaudara) dari seorang ayah bernama Jacobus Johannes Uys (dijuluki Koos Bybel (Alkitab) karena keyakinan agamanya).