This book provides a unique and authoritative account of the current state of EC social security law, focusing on key principles. Despite the subject's importance to millions of people in the EU and partner countries, the complexity of the subject renders it inaccessible to students and non-specialist practitioners. EC Social Security Law explains clearly both the rules governing the co-ordination of the EU's social security systems and those relating to sex discrimination in social security protection.  The author describes which benefits are available and who can claim them. In addition, the author critically analyses the leading ECJ cases that inform decisions on which social security system applies to particular claims. The book concludes with an evaluation of the successes achieved to date and the challenges presented in seeking to ensure that variations in rules on social security entitlements do not raise barriers to the free movement of persons.