A Restatement of the English Law of Unjust Enrichment represents a wholly novel idea within English law. Designed to enhance understanding of the common law the Restatement comprises a set of clear succinct rules, fully explained by a supporting commentary, that sets out the law in England and Wales on unjust enrichment. Written by one of the leading authorities in the area, in collaboration with a group of senior judges, academics, and legal practitioners, the Restatement offers a powerfully persuasive statement of the law in this newly recognized and uncertain branch of English law. Many lawyers and students find unjust enrichment a particularly difficult area to master. Combining archaic terminology with an historic failure to provide a clear conceptual structure, the law remained obscure until its recent rapid development in the hands of pioneering judges and academics. The Restatement builds on the clarifications that have emerged in the case law and academic literature to present the best interpretation of the current state of the law. The Restatement will be accessible to, and of great practical benefit to, students, academics, judges, and lawyers alike as they work with this area of law. The text of the Restatement is supported by full commentary explaining its provisions and roots together with its application to real and hypothetical cases. The Restatement appears as European private law takes its first steps towards harmonization. In providing an accessible survey of the English law, the Restatement will offer an important reference point for the English position on unjust enrichment in the harmonization debates. Also appearing shortly after the United States Third Restatement on Restitution and Unjust Enrichment, this Restatement offers an interesting contrast with American law in this area.