Johannes was born in 1717 and his baptism took place on August 22nd, 1717 in Drakenstein. Johannes' father was Lodewyk Pretorius and his mother was Maria Rossouw. His paternal grandparents were Joannes Pretorius and Johanna Victor. He had two sisters named Anna and Maria. He was the youngest of the three children. He died at the age of 62 on August 22nd, 1779 in Camdeboo.