 In early 1914, the German government sent Detzner to explore and chart the interior of Kaiser-Wilhelmsland, the imperial protectorate on the island of New Guinea. When World War I broke out in Europe, he was well into the interior and without radio contact. He refused to surrender to Australian troops when they occupied German New Guinea, concealing himself in the jungle with a band of approximately 20 soldiers. For four years, Detzner and his troops provocatively marched through the bush, singing "Watch on the Rhine" and flying the German Imperial flag. He led at least one expedition from the Huon Peninsula to the north coast, and a second by a mountain route, to attempt an escape to the neutral Dutch colony to the west. He explored areas of the New Guinean interior formerly unseen by Europeans and surrendered in full dress uniform, flying the Imperial flag, to Australian forces in January 1919.
