This empirical study identifies and analyses what conceptualisations of citizenship emerge in policy thinking around naturalisation and how these conceptualisations have been articulated in citizenship policy and by policy-makers in the two specific cases of the United Kingdom and Sweden. Understanding citizenship as a bounded membership status the research is grounded in a view of citizenship as having content: rights and duties, ideas of identity, perceived virtues or political values. Employing an interpretive methodology the study closely analyses the central policy documents from the period 1994-2007. It also extensively draws on material from over thirty in-depth elite interviews with policy-makers. These include David Blunkett and Ulrica Messing, the ministers responsible during the development of the key changes to citizenship legislation in the respective countries. In the Swedish case the thesis argues that five conceptualisations form the ideational context in which policy articulations of citizenship take place. Interplaying ideas of integration, equality and belonging are reinforced by conceptualisations of citizenship as about a „welcoming‟ symbolism and as „responding to a global, internationalising context‟. In the UK case five conceptualisations also emerge. A strong interlocking of thinking about integration and belonging provides citizenship policy‟s ideational foundation. Adding depth and complexity to this are ideas about diversity, „common values‟, and the presentation of citizenship acquisition as a „journey‟. The final section of the study analyses and compares the findings from the two specific cases. In considering the policy tone around naturalisation it contrasts the attention given to individual effort in the UK with the accentuation of entitlement in Sweden. It also highlights different conceptual approaches to belonging and its relationship with citizenship; with belonging strongly connected to identity in the UK but to the idea of emotional certainty and security in Sweden. This is argued to reflect distinct beliefs about where evolving ideas about citizenship create demands for change. In Sweden, legislative opening to dual citizenship was conceptualised as a necessary response expected of the state. In the UK, the introduction of citizenship tests was conceptualised as the establishment of a legitimate demand on individuals. Approaches in the two cases are also shown to differ in where emphasis lies in ideas about diversity‟s relationship with citizenship. The UK downplays notions of ethnicity while the Swedish conceptualisation accepts pluralism as the reality of contemporary globalisation.