This book studies the evolution of mortgage securitisation togetherwith that of the derivative instruments that they have frequently been combined with. It traces the historical development of securitisation from its roots in various European legal institutions to the creation of its modern form in the U.S.A in the last decades of the twentiethcentury, and explores the Common Law treatment of derivatives, byexplaining how they came to be distinguished from both insurancecontracts and wagers. It makes the case that it was the eventualmerging of mortgage backed securities with credit derivatives thatresulted in securitised products acting as a catalyst for the creditcrunch and the ensuing Financial Crisis, and that subsequentregulation, particularly the European Securitisation Regulation hasbeen significantly shaped by the erroneous perception ofSecuritisation as a principal cause of the crisis.