It is now well established that the law of unjust enrichment forms an important and distinctive part of the English law of obligations. Restitutionary awards for unjust enrichment and for wrongdoing are clearly recognised for what they are. But prior to the last decade of the twentieth century the very existence of a separate law of unjust enrichment was controversial, its scope and content matters of dispute. In this collection of essays, a group of leading scholars reappraise some of the landmark cases in the area. Their investigations shed new light on some classic decisions, and persuasively invite readers to think again about some well-known authorities.