 He was well into the interior when , on 4 August 1914 , Britain declared war on Germany . As World War I spread to the Pacific , Australian troops invaded German New Guinea , taking the German barracks in Herbertshöhe ( Kokopo ) and forcing the defending German colonial troops to capitulate on 21 September after their defeat at Bita Paka . At the beginning of October , he was still unaware of the state of war that now existed between his country and the Commonwealth . 
