In Bancoult, a majority of the House of Lords upheld the British government's use of the royal prerogative to expel the population of the Chagos Islands from their homeland. The majority acknowledged that the government's treatment of the Chagossians was disturbing, but held that the law left them with no choice but to hold the orders valid. In this article, I draw a parallel between this decision and the 18th-century judicial response to the Zong affair—where over a hundred slaves were thrown off a ship to drown in the sea. Both decisions are cloaked in formalist rhetoric but, as I show through an examination of the law as it stood prior to each of the decisions, the actual legal reasoning in both decisions is so without basis as to be unsustainable on any formalist or legalist account. Rather, the decision in Bancoult, like the decision in the Zong, shows all the hallmarks of being a purely pragmatic one, prompted by broader concerns as to the practical impact of a contrary decision and the precedent it would set. The inherent limitations of this mode of judicial reasoning make its deployment in Bancoult troubling.