Sir Humphrey Gilbert that I believe was the first to voyage to the new world of England in 1583.
Answer:
I'm pretty sure it's with military force.
The British used the idea of imperialism to to promote enlistment during the war by implying that if Britain lost, her empire would be lost as well.
Australia is a Federal Country. The country is known to have a powerful central government, and has states/provinces around it that are provided with sufficient self-rule. However, it's still the central government that rules above all matters in Australia.