What does it mean to treat people as equals when the legacies of feudalism, religious persecution, authoritarian, paternalistic and oligarchic government have shaped the landscape within which we must construct something better? This question has come to dominate much constitutional practice as well as philosophical inquiry in the past 50 years. The combination of Second Wave Feminism with the continuing struggle for racial equality in the 1970s brought into sharp relief the variety of ways in which people can be treated unequally, while respecting the formalities of constitutional government. Above all, what these two great political movements made plain, is that a concern for group inequality and, specifically, group injustice must figure in the formulation and adjudication of individual rights, if legal protections for equality are adequately to combat the causes of inequality. Getting to grips with that challenge, it became obvious, required going beyond the familiar analyses of inequality inherited from Liberalism and Marxism, given the many different ways in which people can be equal or unequal.(Hackett and Haslanger 2006, 3 - 15) In the first part of this chapter, I will seek to illustrate these claims, by focusing on efforts to reframe the theory and practice of constitutional equality in light of demands for sexual and racial equality. I will then show that analytic philosophy has also come to recognise the various non-reducible dimensions of equality in ways that reinforce the claims of critical legal theory, even as philosophers highlight their disconcerting consequences. If equality has multiple irreducible dimensions, conflicts between the legitimate demands of equality are unavoidable features of law and politics, even in the best possible world, and are likely to be particularly painful when set against a background of historical injustice. The chapter concludes with the challenges to democratic constitutionalism, and the scope for constructive responses to those challenges, which the rapprochement between critical and analytic thinking on equality suggests.