Abstract: CSR (Corporate Social Responsibility) was introduced into French business law by Article 116 of the NRE Law (Law on New Economic Regulations) of 15 May 2001, although it was not referred to by that acronym at the time.This article marking the discreet birth of what was still private non-financial reporting of information of a societal nature, and on commitments in favour of sustainable development, concerned only listed companies.This non-financial information is a precious component of corporate governance and has become a must-have for almost all companies (large and small, listed or not, public and private), organisations, mutual companies and local governments.In no time at all, it has become everybody's business, although at the risk of being no more than a mere tool of managerial seduction.No one can deny that this CSR groundswell has brought unprecedented upheaval to company, labour and environmental law, as CSR insinuates its way into all the existing branches of law and causes them to influence each other (financial law, environmental law, labour law and business law).It is modifying our relationship with business law in general, to such an extent that the initial criticisms have gradually given way to a particularly refreshing construction phase consisting in studying the relevant standards, and even to a worthy consensus.CSR appears to be something of an enormous jigsaw puzzle with pieces from all kinds of different origins.The key (and perhaps ultimate) question is whether it constitutes a new branch of law, although it might be better described as the sap that enables the existing branches of law to grow further and support the challenges of the twenty-first century.Looking through the remarks and articles published on the advent of CSR in French business law, I have noted a metamorphosis both of CSR itself and of business law, making it possible to attempt to assemble the scattered pieces and seek a common thread, looking upstream at corporate governance itself, which has undergone the many influences of CSR (in very different ways), and downstream at the role of the various stakeholders.Companies are in the front line in CSR and have been given primary responsibility by the European Union for driving the sustainable and inclusive growth it is targeting, a growth that is sustainable for future vii