The contact period rock art of northern Australia provides unprecedented insights into Aboriginal cross-cultural experiences during the last few hundred years. Northwest Arnhem Land, Australia, has an extensive rock art assemblage and a complicated history of interactions between Aboriginal communities and island South East Asians (Macassans), colonists, explorers, missionaries, buffalo shooters, and more. This contact period rock art offers a unique opportunity to explore a variety of questions relating to cross-cultural interactions and artistic responses to new people, objects and ideas. In this paper we argue that a dichotomy exists in the number of European and south-east Asian themed rock art motifs. We suggest that there is an underlying theme in the proliferation of European related imagery relating to threats to Indigenous sovereignty. Our findings suggest that rock art illustrates the Aboriginal community's responses to both groups and their experience of the existential threat posed by European intruders. The apparent lack of rock art relating to south-east Asian interactions, although perplexing, may in fact provide circumstantial evidence for a very different type of interaction between some northern Australian and southeast Asian communities.