The quest for policy integration crystallized in the 1990s as awareness was growing that the current supply of narrow, sectoral, and little coordinated, or even overlapping and conflicting, policies could not cope efficiently and effectively with contemporary complex, cross-cutting and interdependent socio-environmental problems. Combining and coordinating policies properly promises to address this institutional misfit, "add value" to policies, support planning at national and sub-national levels, and facilitate the transition to sustainable development more generally. This book proposes a comprehensive conceptualization of policy integration and negotiates pertinent theoretical, methodological and applied issues from the perspective of selected EU policies - rural development, regional development, transport, social, economic, environmental, water resources, and biodiversity policy. Mediterranean desertification, an exceptionally complex socio-environmental problem, is used as an illustrative example as the idea for this book transpired while researching the topic of policy making to combat desertification in the context of MEDACTION, an EU-funded research project.