Johannes Franciscus Leloux was a military man in the regiment Raders. This regiment was garrisoned at Bergen op Zoom in 1768, at Den Bosch in 1771, at Nijmegen in 1773 and at Doesburg in 1783. All places where his children were born. The army list of the compagny of lieutenant-colonel Oostdijck in the first Bataillon of the Regiment Infanterie from lieutenant-general van Raders, made while garrisoned at Tournais (25 March 1781), stated that Johannes had a length "op kousevoeten van 5 voet, 6 duim en 1 streek" and he was 39 years old.
Marriage-register "Trouwboeken van de Nederduits Gereformeerde Gemeente te Bergen op Zoom, 1751-1772" stated that Johannes Francis LeLoux is born in Nieupoort, while the birthregister of his son Franciscus Johannes stated that he was born in Ieper. Both Ieper and Nieupoort were so-called Barriertowns, where dutch armies were stationed to help the Austrian rulers of Belgium at that time to protect against France until 1781. (source: "Parenteel..." by Frans Leloux, 1995)