Ponies' Monarchy of New Equestria
Government: Federal Tyranny
Governor of New South Wales, Sovereign of Equestria: Princess Celestia (aka Trollestia)
Governor of Victoria: Twilight Sparkle (Minister of Friendship and Magic)
Governor of Queensland: Pinkie Pie (Minister of Fun, High Admiral)
Governor of Northern Territory: Fluttershy (Minister of Animal Affairs)
Governor of Tasmania: Rainbow Dash (Minister of Weather, Air Marshal)
Currency: Golden Coin
Economic Policy: Laissez-faire
Social Policy: Welfare State
Foreign Policy: Pony Hegemony
History:
After the Cataclysm, Australia was shattered and divided in local communes controlled by chieftains. But the people wanted the old days back, and slowly these communes started to find each other and integrate in the old Australian regions.
The old chieftains, however, wanted to maintain their power, and while the strongest became rulers of entire regions, the rest integrated a network that would later become the deep and oppressive bureaucracy of the Great Fiefdom of Australand, the union of most of these communed regions in a unified government.
This structure implied constant fights and wars between communes to control the regions once the leaders died, until a mysterious figure known as Magnus took control of New South Wales and allied with the ruler of Victoria, Sarah Browe.
Together, the power of these two regions made Magnus and Browe able to subdue the rulers of Queensland, Tasmania and Northern Territory, thanks to political tricks and soft power mainly.
They also crushed the regions which refused to be annexed, but the inestability of the country was too high to continue such enterprise, and for years the efforts of Magnus went to propaganda and establishing a pantomime of federal democracy, always controlled by his loyal chieftains, who always refused to lose power. This way, the old system merged with a new one, creating a nightmarish bureaucracy which is able to provide public health services and to sustain a welfare state vital to keep the country united.
When the conversion was completed, Magnus was revealed to be Joshua Browe, Sarah's husband, who was elected governor of New South Wales without need of fraud, and chosen by his equals as Coordinator General, an euphemism for Supreme Dictator.
Now, he is ready to unify Australia as Aussieland and add New Zealand and Oceania to his booty. Until a new force appeared.
Through a portal opened with the magic of Friendship, funnelled by Twilight Sparkle, Celestia and the high society of Equestria ran away from Princess Luna, who finally took over the original Equestria. As a result of the magic explosion, Humans in Oceania and random places all over the world became either ponies, unicorns or pegasi, completely disoriented and left to the will of the new coming pony aristocracy.