Duquesne joined the Boer forces again for the Battle of Bergendal, but his unit had to fall back to Portuguese East Africa (present-day Mozambique). Many were captured by the Portuguese and sent to an internment camp in Caldas da Rainha near Lisbon. For Duquesne, this would become the watershed event, as Ronnie states, "life would never be the same for him  ... In a few months, he would be launched on a forty-year career as a professional spy and counterfeit hero – a man who would constantly reinvent himself to suit the needs of the moment."