The Nova television programme Nazi Prison Escape, a shortened cut of a British documentary series, was based on his books about Colditz.
In March 1913, Eggers was called up for military service and was, on his request, posted to the 2nd Battalion of Marine Infantry (Seebataillon) at Wilhelmshaven.
His battalion commander was the famed Paul Emil von Lettow-Vorbeck, who after six months personally promoted Eggers to Gefreiter.
He started as LO3 (Lager Offizier 3 or duty officer)[1] and was faced with rebellious, anti-German POWs from Poland, France and the UK, who took every opportunity to harass their captors.
Lieutenant Damiaen J. van Doorninck, a former Dutch POW, wrote in his foreword for Eggers's book that:This man was our opponent, but nevertheless he earned our respect by his correct attitude, self-control and total lack of rancour despite all the harassment we gave him.His success at stopping most attempts to escape Oflag IV-C made Eggers a subject expert.
[1] After the liberation of Colditz Castle by the U.S. Army, Eggers retired from active service and returned to his post as a teacher in Halle, Saxony-Anhalt, as he was able to prove that he had never joined the Nazi Party.
Charged with crimes against humanity, spying and supporting a fascist regime, he was sentenced to ten years of hard labour.