Daniel Roxo was born in Mogadouro, Tras-os-Montes. As a young man he migrated to Niassa Province in 1951, where he settled as a professional hunter and safari guide. When the Mozambican War of Independence broke out in 1964 Roxo formed his African trackers, servants, and European acquaintances into a private militia, hunting FRELIMO combatants for government bounties. Disillusioned by Portugal's promise to hand Mozambique to Samora Machel's incoming government, Roxo supported an abortive coup d'etat by anti-FRELIMO forces in Lourenco Marques on September 7, 1974. He emigrated to South Africa the following November, joining the South African Defence Force. After completing Special Forces selection, Danny was seconded to Bravo Group (later 32 Battalion).
Daniel was awarded the Honoris Crux for bravery during Operation Savannah, 1 November 1975, for an action during the Battle of Bridge 14, an engagement during which he single-handedly killed eleven enemy soldiers. Bridge 14 was situated on the Nhia River, en route from from Cela to Quibala. South African mechanized contingents deploying to the south had routed a FAPLA unit some time prior, and the retreating Angolans had demolished the existing structure. However, since Colonel Jan Breytenbach could not actually ascertain this from his forward positions, he ordered Roxo to conduct a more thorough reconnaissance. Roxo subsequently arrived at the river with four Eland-90 armoured cars; his patrol came under heavy mortar fire from an opposite bank and two of the vehicles withdrew, leaving Roxo