We start by surveying the different issues that fall under the umbrella of ‘multiculturalism’. We then sketch the trajectory of British multiculturalism since 1945, and examine its broader legal and philosophical contexts. This narrative highlights the empirical and theoretical connections between multiculturalism and decolonisation, and that the conceptualisation of multiculturalism in political theory is more wide-ranging than in law or policy. This helps foreground neglected aspects of British multiculturalism in policy and law, and suggests we should widen the philosophical scope (...) of multiculturalism even further. We then summarise the papers and draw out the connections between them. We argue that a deeper understanding of contemporary British multiculturalism inexorably leads us back to fundamental philosophical and practical questions regarding the structure and purpose of the British polity, and conclude that this indicates the need for greater polycentricity in governance. (shrink)