James Dunk is not the first Australian historian to notice that mental breakdown was surprisingly common during the first two European generations in New South Wales. Malcolm Ellis linked the ‘Botany Bay disease’ to rheumatic fever, rife on shipboard, which ‘ruined the lives or unbalanced the minds of … many pioneers’. Manning Clark spoke of sanity collapsing ‘under the weight of the vast indifference of nature, of loneliness and mockery’. More recently, Jonathan Lamb has suggested that it was all a result of endemic scurvy.

Bedlam at Botany Bay offers the most subtle and suggestive explanation so far by linking mental disability with a type of absolute power that, by his account, went from top to bottom of the settler community. We know, certainly, that unaccountable, unfeeling power can cause madness. It is easy to imagine that the most damaging thing about confinement on Manus Island and Nauru, and a likely cause of mental derangement, is the realisation that freedom – when and how – is entirely unpredictable. There must be something especially bitter in the knowledge that our long suffering is the work of other human beings, who could end it when they like.

In early New South Wales, power was usually less arbitrary than this. It was more obviously governed by law, but, as Dunk’s many stories show, it was typically personalised in some way and dramatically unequal. In telling those stories, he conjures up a hopeless pain, uncovering, as he says, a hitherto altogether too obscure dimension of the settlement project. Settlement could be deeply unsettling.