In our world's history, traders and smugglers from Indonesia had bases in Australia. But as Australia was not suitable for rice agriculture, and, except near
Adelaide the soil is poor, these bases never grew to be settlements.
On this Q6 world, it was different. As with the Adelaide area, there was a volcanic period only a few million years ago on Australia's Northwest Coastal area. As dry rice crops were possible, the bases grew to become settlements and small kingdoms. When
Majapahit collapsed Javanese Hindu-Buddhists that couldn't go to Bali fled to these settlements. At this time it gained the name Benteng kidul (Southern Fortress).
The Local year is 1879.
Ned Kelly has allied with the Sultan of Benteng kidul (who also has grievances with the government of Australia and the British Empire) to create an independent state on the Australian continent. The Bush Ranger ia becoming a Field Marshall.