Private and public organizations increasingly form networks and ecosystems to remain competitive and deal with wicked collective action problems. Given the growing prevalence of network-based collaboration, it is astonishing how little we know how members actually lead the networks in which they are engaged. The book addresses this concern, theorizing and describing the practice of leading in networks. To this end, it draws on the practice turn in network and leadership studies and presents insights from two qualitative longitudinal case studies conducted in the Swiss healthcare sector. The book contributes to the current debate on leadership in networks and ecosystems, offering a novel theoretical framework that may guide future scholarly investigations and practical action in this important field.