Cyber norms and other ways to regulate responsible (state) behaviour in cyberspace is a fast moving political and diplomatic field. The academic study of these processes is a varies and interdisciplinary field. However, to date, much of the literature has been organised according to discipline, with rising interests in the field of international law, political science and IR, and international governance. Both the broader field of the study of international cyber security and internet governance, as well as the subfield of norms and state behaviour in cyberspace are relatively young, making their way into specialised journals. This volume brings together researchers from various academic disciplines around the theme of responsible state behaviour in cyberspace. The authors come from disciplines such as international law, IR, business studies, political science and philosophy. The collection is divided into three parts. The first looks at current debates in and about international law in cyberspace. The second focuses on power politics and the way institutions (international organisations and legal instruments) adapt to the realities of cyber space and digital conflict. It also looks at the normative behaviour of states including China, Egypt and the Gulf States and sub-state actors such as intelligence agencies. The third part takes a critical look at multi-stakeholders and corporate diplomacy. How do global tech companies shape their role as norm entrepreneurs in cyber space and how do their cyber diplomatic efforts relate to their company identity?