When Australia was invaded in the late 18th century, white settlers brought with them viruses that had never existed in that part of the world before including influenza for which native peoples had never established any prior immunity. These viruses alone wiped out entire tribes of peoples. I refer to them as 'peoples' in the plural because although indigenous Australians are often lumped together as a single group, there were 500 distinct languages spoken around the continent at the time of the British invasion, which should give us some idea of the diversity and cultural richness that existed, especially when we compare this to Europe where there are only around 50 distinct languages today. This richness developed over a very long time, modern homo sapiens settling the continent of Australia some 50,000 years ago, before they'd even set foot in Europe. Yes,
Following initial white settlements, Aboriginal deaths were often of a more deliberate nature with dozens of recorded massacres occurring throughout the 19th and early 20th centuries. Many Aboriginal people were also driven off their land and thereby left to starve after being deprived of traditional sources of food and water.
It wasn't until as late as 1962 that indigenous Australians were even given the right to vote, and for a hundred years ending in 1969, the Australian government had a policy of forcibly removing Aboriginal children from their families in the hope of assimilating them into the dominant white culture. The youngest members of these 'stolen generations' are only in their 40s today and can still clearly remember the trauma of being separated from their mothers as children and forced to live in state-run orphanages.