Unjust Enrichment and the Role of Legal History in England and Australia

Private law evolves slowly over decades or even centuries. Without the benefit of hindsight it is not always obvious that any change has taken place at all. Yet this observation does not inevitably hold true. The emergence of unjust enrichment in the final decades of the twentieth century is a clear counterexample. Little more than a generation has passed since Lord Diplock could state that ‘there is no general doctrine of unjust enrichment recognised in English law'. In England such remarks would now be all but impossible. What was once an academic backwater has assumed great importance in claims involving enormous sums of money. The decision which gave unequivocal judicial approval to unjust enrichment as a distinct legal category in England has not yet celebrated its 25th birthday. Judicial recognition of unjust enrichment was also late in coming in the High Court of Australia and the New Zealand Court of Appeal. The Supreme Court of Canada was more prescient in this regard, but the law in that jurisdiction has veered off in a very different direction to the rest of the Commonwealth