Dovecar was born at Tužno in Croatia. He enlisted in the Foreign Legion on 5 April 1957 at Marseille under the name of "Paul Dodevart," claiming birth in Vienna, Austria on 20 February 1938. After training at the Foreign Legion training base at Mascara, he was assigned to the 1st Parachute Regiment (Foreign Legion). Dovecar took back his original name on his promotion to sergeant on 16 June 1960. Dovecar participated in the Algerian War, receiving three citations and one combat wound. After his participation in the Algiers putsch of 1961, he decided to break his contract on 27 April 1961 to join the Organisation armée secrète (OAS).