This book provides a critical comprehensive summary of the coevolution of telecom markets, rules and public institutions over the last 25 years, focusing on the challenges that regulators and policy makers have been facing. Even if the perspective of the book is European (as the EU regulatory framework is examined), most of the economic and institutional issues addressed are common to all telecom markets in advanced economies. The book addresses some traditional fundamental topics in the telecom regulation literature, as well as some hot-button topics in the current policy debate, e.g., ultrafast broadband and 5G networks, the relationship between investments and competition, the sector digitalisation and the role of OTTs. All these are relevant to students, researchers, and policy makers interested to get a sound understanding of the sector, its many dimensions and coevolutionary patterns.