This is the third and last part of the "Principles of European Contract Law" prepared by the Commission of European Contract Law under the chairmanship of Professor Ole Lando. Parts I and II were published in 2000 and have attracted a growing volume of secondary literature. This volume follows the same pattern - a set of proposed Articles drawn up by the Commission, followed by comments and national notes containing a wealth of comparative law. The subjects dealt with in Part III are:- plurality of debtors and creditors, assignment, substitution of new debtor and transfer of contract, set-off, prescription, illegality, conditions and capitalisation of interest.