The question was asked - how well do you know your Australian history?
Obviously there were bits that I wasn't aware of -
The proclamation of 'North Australia' in 1846 led to a slice of New South Wales being sandwiched between Western and South Australia (the state of South Australia was proclaimed in December 1836). The South Australian border did not move and become a common border till 1860, when the line moved from 129 degrees to 132 degrees.
The 1846 'North Australia' colony was established by Queen Victoria and an Act of the British Parliament in February, on advice from then Colonial Secretary Gladstone. It was destined to be settled by pardoned and reformed British and Australian convicts. The proposal was opposed by the NSW government who saw it as re-introducing transportation. The proclamation was revoked in November by the Queen when Earl Grey became Colonial Secretary.
The history is showcased in this GIF from the FindMyPast people, fascinating!
Places like Darwin have changed allegiances about 6-7 times.