This introductory chapter explores the development of the civil society sector in Europe, emphasising the processes of professionalisation and NGOisation that result in the concentration of power and resources among a few key actors. By integrating insights from civil society studies and elite studies, the book addresses a significant research gap concerning power stratification within civil society. The concept of a “civil society elite” is central, focusing on individuals in leading positions within major organisations. The Italian context is highlighted, underscoring the third sector’s dual role in providing social services and advocacy. Key terms like “Third Sector” and “Ruling Class” are introduced, with the term “elite” being justified with reference to C. Wright Mills’ perspective on power elites. This chapter outlines the book’s structure, which includes an in-depth analysis of the Italian context, the organisational landscape, and leader composition, comparisons with professionalisation processes within the UK, career trajectories at the EU level, and subjective perspectives on elites in Sweden. This comprehensive framework sets the stage for a detailed examination of power dynamics and elitisation within the civil society sector in Italy, offering comparative insights from other European contexts and discussing the implications for civil society’s role in democracy.