Details of Esswein's entry into military service are not available. However, Esswein transferred from ground service to aviation in mid-1915. On 30 October 1917, he was assigned to
Jagdstaffel 26. He scored his first victory, shooting down a
Sopwith Camel on 15 November. He was then slightly wounded in the right eye on 27 November. of the
Luftstreitkräfte at Erchin, France. When he returned to the squadron in early 1918, a new
Fokker Dr.I triplane awaited him. He used it to shoot down another Camel on 2 February, three more the next day, and two more British fighters on the 5th, one of which was the
Royal Aircraft Factory SE-5 of
No. 84 Squadron RFC's Lt. Cyril Ball, brother of English ace
Albert Ball. By 26 March 1918, he was a double ace with ten victories. On 31 May, he increased his tally to a dozen with his two last victories. He was awarded the Military Merit Cross on 3 June 1918 to join his
Iron Crosses, and later awarded his home kingdom's
Military Merit Order. On 16 July, in one of the pioneer usages of a parachute, he successfully bailed out of his burning plane after being shot down attacking a balloon. Five days later he was unable to repeat the feat and was killed in action in another flaming aircraft over
Hartennes-et-Taux, France. ==Sources of information==