I greatly admire people who can capture quality photos of butterflies on the wing, especially having tried to myself. Apologies, for these photos are not (quality, that is)! These 2 predominantly black butterflies with white markings were fluttering around each other over quite some distance and time. However their makings were distinctly different. One had only white on black, an almost diagonal line through the top corner of the fore wind, (both upper & lower sides), and a large white patch on the hind wings, (again, both upper & lower sides). It is the butterfly closest to the RHS in photos 1 & 2. The other butterfly (Left-most in photo’s 1 & 2), whilst also predominantly black, had distinct red markings towards the outer edge of the hind wing, below that wings large white patch, and a large white patch on the fore wing which merged to grey towards the outer edge, and the black edge intruded into the top of that white patch (photo 4 particularly demonstrates the latter, while photos 1 & 2 (butterfly to the LHS) show the red markings, albeit unclearly). I’m tempted to think this is an Orchard Swallowtail. These, and/ butterflies very similar in appearance, are common at this site (Copmanhurst NSW North Coast) from approx. mid Spring to mid-Autumn. (Another is at Sighting 4667491)