This chapter presents the fundamental assumption of this volume, which is to acknowledge the transformative impact that AI systems can have and explore the connection between the fields of AI sovereignty, transparency and accountability, engaging with various policy frameworks that can regulate such systems. Particularly, this paper proposes a conceptual framework to understand this volume and presents the book contributions, arguing that discussions on transparency, accountability, and sovereignty in AI governance are highly interconnected. Based on the previous work led by Belli, we define AI sovereignty as the capacity to understand, develop, and regulate AI systems, in order to exercise self-determination, power an control over such systems. We argue that the assertion of AI sovereignty, transparency, and accountability play a key role shaping the understanding, development and regulation of AI systems towards paths that align with the protection of fundamental rights, the respect of existing legal requirements, the promotion of sustainability and, ultimately, the maximisation of the public interest. In doing so, this introductory chapter provides to the reader with a useful guide to approach the concepts analysed in the different contributions collected in this volume, while highlighting the connections between such contributions. The chapter acknowledges that the concepts examined by the authors of this book have been given much attention throughout policy debates and have been framed and defined in highly heterogeneous fashion, depending on the different public discourse arenas, and stakeholder interpretations. In this perspective, the goal of this chapter is to present the diverse issues that will be explored along the volume, enticing the reader to venture in the chapters of this work to further explore them.