Political map of Australia, New Zealand & the Southwest Pacific 24 September 1914 (Conquest of the German Pacific): The Great War (World War I) opened in the Pacific with a string of easy victories for the New Zealanders and Australians as they seized Germany's scattered Pacific colonies (Asian and Pacific theatre of World War I). Meanwhile they eagerly sent troops to fight under British command (Australian and New Zealand Army Corps) in the altogether more serious war underway in Europe.