Abstract
The principle of pacta sunt servanda (agreements must be respected) is one of the basic principles of modern private law. Although often referred to as a principle of Roman law, in fact Roman law was based on the opposite principle, that is, on the principle of ex nudo pacto actio non oritur.
Despite this, it was Roman law, on the sources of which the principle of pacta sunt servanda was formulated. The article deals with the genesis of the binding nature of bonds in Roman law and defines the main milestones aimed at enshrining the principle of pacta sunt servanda in valid private law.