Marseille completed his training at a Fighter Pilot School in Vienna to which he was posted on 1 November 1939. One of his instructors' was the Austro-Hungarian World War I ace Julius Arigi. Marseille graduated with an outstanding evaluation on 18 July 1940 and was assigned to "Ergänzungsjagdgruppe" Merseburg, stationed at the airport in Merseburg-West. Marseille's unit was assigned to air defence duty over the Leuna plant from the outbreak of war until the fall of France. On 10 August 1940 he was assigned to the Instructional Squadron 2, based in Calais-Marck, to begin operations against Britain and again received an outstanding evaluation this time by commander Herbert Ihlefeld.