A bushranger combines light rum, Dubonnet rouge and Angostura bitters with a lemon twist. My recipe from The New York Bartender's Guide puts the rum and Dubonnet in 4:3 ratio. I'm always impressed by how the bitters, even in tiny quantity, plays such a defining role in the flavoring of any drink. In the bushranger, the Dubonnet, a wine-based aperitif, brings out the warmth of the bitters more than the other way around. The end result is pleasantly sweet and sufficiently wintery according to my wife.
Bushrangers were escaped convicts during the early British settlement of Australia. In national folklore, they represent rebellion against authority. While the drink is presumably Australian in origin, I couldn't find a precise history.