Murnau had a great interest in acting from a young age, and he entered Max Reinhardt's acting school after studying art history, literature and philology. However, the First World War led to Murnau volunteering for service, and he was promoted to a a reserve officer in the Prussian 1st Guards Infantry Regiment in 1915, serving on both the Western Front and in Latvia before transferring the Kaiserliche Luftstreitkräfte.
Somehow, Leutnant der Reserve Murnau managed to squeeze his 210 cm tall body into a First World War-era aircraft, and in April 1917 he started training with Flieger-Ersatz-Abteilung 10 in Böblingen. He then went on to a Offizier-Fliegerschule-Lehrkurs in Warsaw, and finally to a Beobachterschule in Jüterbog. In September 1917 Murnau was posted to Fliegerabteilung (Artillerie) 281 at Chateau Hasard near Lorquin (aptly called Schloss Zufall by the Germans) from where he flew reconnaissance missions over the Verdun area as an observer in Rumpler C.IV and Aviatik C.I two-seaters. He does not seem to have had great luck with his pilots, since it is claimed that he survived in all eight crashes, albeit without serious injuries.
Murnau in front of an Aviatik C.I.
Murnau's colleague, Leutnant Schramm recalled how Murnau would entertain his fellow fliers: "It was 1917 and our regiment of flyers was quartered near Verdun, in a beautiful but rather melancholy chateau abandoned by its owners. Murnau ... was always to be seen by his aircraft, personally making sure that it was serviced properly... On every mission, every flight he did everything as carefully and conscientiously as he arranged his room. ... In the evening, when we sat around in the mess, Murnau had another duty to perform. It was always the same. As the fire threw its dancing, changing shadows on the shifting group of young officers, Murnau had to recite Der Todspieler (The Pianist of Death). I don't know whether he used to do it to please himself, but he did it conscientiously, with the emphasis and the strange intonation, half pathetic and half comic, that proclaimed him the pupil of his great master [theatre director Max Reinhardt - IGR]. He would recite the poem in a ringing voice, his gaunt face quivering [and] our Captain was completely captivated... Outside it was dark and cold, with every so often the dull rumble of the guns. But we sat there quietly, and we were all moved as we listened to the tall Murnau reciting."
On December 4, 1917, Murnau was the observer in what seems to have been a Hannover CL with number C9288 piloted by a Leutnant Meyer. The pilot was to ferry the aircraft from Strasbourg to the unit's airfield in Lorraine. However, the pilot lost his bearings in the heavy clouds, and a storm carried the aircraft in the direction of neutral Switzerland. Swiss onlookers noticed a German aircraft circling over Basel for a good 20 minutes just after four o'clock before landing on a football field near Allschweiler Bachgraben. Murnau and Mayer embarked the aircraft, and they were quickly apprehended by Swiss police and military personnel. Although the Swiss authorities found that the aircraft was armed with a machine gun, it carried no ammunition.
Murnau's aircraft after landing i Basel.
Being interned in Andermatt, the war may have been over for Murnau, but be became friends with Alphons Staehelin-Zahnd (1882-1943), a patron of the arts. Murnau was eventually relocated to a Pension Felsberg in Lucerne, and he was allowed to engage theater communities in Switzerland. He directed the Swiss popular play Marignano that opened in June 1918 - receiving good reviews and a prize - before being repatriated to Germany at the end of the war and once again engaging in film. It is claimed that his wartime experiences on the ground and in the air influenced Nosferatu, and considering the horrifying imagery of the film, that may very well be true.