In recent decades the categories once used with little hesitation to denote identities and differences have begun to lose their stability. C. A. Bayley notes that as recently as the 1970s the term ‘British’ was taken to refer to ‘an old national identity’, while the term ‘indigenous peoples’ referred to ‘a set of fixed racial groups within the empire’. Now historians have begun to treat ‘Britishness’ as a ‘recent, fragile and contested ideology of power’, while recognising that the term ‘indigenous peoples’ was ‘fractured and contested from the beginning’. With the rise of postcolonial studies a new awareness of the inadequacy of dichotomous notions of difference has undermined the distinction between centres and peripheries, as observers increasingly insist on the interrelations and reciprocal influences at work in the dynamics of empire. These developments occurred, like the new understanding of nation-building, in the context of rapid changes in the economic and political order across the globe: the decolonisation that began in the wake of the Second World War, and the consequent production of new national histories that challenged imperial narratives of shared political and cultural history; the rise of civil rights and feminist protest movements; increasing migration and mobility; the deregulation and globalisation of markets; and the common experience of, in San Juan's word, ‘the spectacle of heterogeneous languages and practices coexisting with the homogenizing scenarios of everyday life’.