Tackling health inequalities must be a central plank of public policy for any government, so I was honoured to be asked to undertake the review of health inequalities for the Labour Government in 1998. I hope that the report from the review, “The Independent Enquiry into Inequalities in Health”, has helped to shape the policy direction, and influence the targeting and delivery of services, in tackling inequalities. We have moved a long way in our commitment to tackle health inequalities since then. The evidence base about “what works” is still fairly weak, but there is now a commitment to address this. Resources are going into research and development to advance our knowledge and understanding of what works. In parallel with that we need to be able to measure inequalities, in order to plan, set targets, monitor and evaluate. I recommended in my report the need to establish mechanisms to monitor inequalities in health and to evaluate the effectiveness of measures taken to reduce them. This book is therefore a welcome contribution to the resources available to people working to reduce inequalities in health in their communities. I commend it to anyone involved in addressing health inequalities. The measurement of inequalities is a complicated and convoluted science, but this book brings together much of that science in a rigorous but accessible way. It is a rich source of information and will contribute to advancing our knowledge and practice, with the ultimate aim to reduce inequalities and to make this country a more equitable society.