This chapter presents a historical overview of the emergence and evolution of ESG assets and, in particular, analyses the main market trends that have been observed in recent years in relation to these assets. The authors intend to present a summary of the main moments and phases that these assets have gone through, from the moment of their appearance in 2007, the year in which the European Investment Bank carried out its Climate Awareness Bond as a test issuance. The movement associated with the issue of these assets is initiated by supranational entities with little homogeneity and no fixed conventions. To overcome this impasse, the green bond principles emerged and a process of defining the characteristics of these assets began, with a particular focus on transparency and the governance process. From this stage onwards, the market showed interest in these financial products and hence the emergence of a harmonising movement regarding green bond standards in which Europe seems to have taken a leading role.