This book is concerned with the social divisions of later life. It is not primarily a critique of inequality in later life, or a polemic for greater social justice in old age. Rather it is an attempt to illustrate how later life has become a more diverse social location than ever before. That diversity includes inequalities and differences that are structured by the social relations of work, the organisation of households and the changing nature of the economies of contemporary developed societies. However, it goes beyond this, exploring both what structures divisions and what structures difference. We have added the role of the body as a marker of division and difference in addition to the classical structural accounts of social division. While the disability movement has sought to reframe bodily impairments in terms of unequal access, and the anti-ageism movement has sought to critique the ideology of bodily decline by which age is culturally, politically and socially represented, we have considered the body as both a site and a source of social division that has acquired much greater salience within our ageing societies. We have also sought to identify how later life serves as both a site or social location of social divisions and an intersection mediating between social differences and social divisions. Just as class operates differently during working life, compared with how it operates before and after working life, so too we argue do other divisions, like gender, ethnicity and disability. Using later life as a lens to interrogate the nature of social division and social difference is as important as using social division and difference to illuminate the changing nature of later life. By emphasising this reciprocity, we hope to show that age and ageing are also matters of importance to social theory and the social sciences more generally.