Behold all, the glorious nation of North Australia!
After the 1840's North, Central and Southern Queensland (Queensland at this time still incorporated the Northern Territory) all seceded from greater Queensland. As Federation came all three states disputed control of New Guinea (invaded by North Queensland in 1880) as well as power by the Federal government. All recognized the benefits of a united North Australian Commonwealth, formed in 1905.
Encouraged by this act West Australia stayed out of the Federation and a border dispute with Northern Australia led to a redrawing of the border. North Australia fought with the Allies in both World Wars, taking Papua from Germany to form the state of Papua New Guinea. Twice North Australia has come to the edge of war with Indonesia, acts which have born fruit to the newly independant nations of West Papua and East Timor. North Australia has the second most effective army in Oceania and has the atomic bomb.
Note: I've excluded the Gold Coast from my glorious, popular nation because well...its mostly owned by Japanese and Chinese businessmen and is more of a New South Welsh city than anything else now.