Early colonisation
In 1788, the first fleet of British ships landed at Sydney, Australia. Thomas Townshend, a member of the House of Commons who would become 1s Viscount Sydney, made the decision to create a British colony in Australia. This was done for various reasons.
One, it would serve as an alternative to the process of transporting convicts to North America, as the American colonies gained their independence. Transportation was often an alternative to the death penalty, which was used for quite a number of crimes in those days, even minor ones.
Secondly, Australia was considered an important base to curb French expansion in the Pacific. In the span of just over 150 years, more than 50,000 convicts were transported from Great Britain to Australia. Penal servitude sentences ranged from seven to fourteen years. Occasionally, they would receive life sentences.
https://www.family-tree.co.uk/news/prison-island-australia-and-britains-shared-past/