Health Action Zones (HAZ) were one of the earliest and most prominent area-based initiatives launched by the New Labour government in England soon after it came to power in 1997. Written by members of the team undertaking the national evaluation of HAZ, this book examines the initiative’s development and impact from a variety of perspectives. It outlines important features of the social, policy and evaluative environment within which HAZ were established and discusses enduring themes such as building and developing capacity with diverse and unequal partners within complex policy systems. Multidisciplinary in nature, the book provides in-depth analysis of a key policy initiative, offering guidance on how best to design, implement and evaluate future initiatives intended to deal with fundamental social problems.