The relationship between politicians and civil servants is ambiguous and potentially problematic in democratic terms. The aim of the thesis is to examine this relationship in the Swedish core executive, Regeringskansliet. More specifically, the analysis emphasises the respective role expectations of the two groups when interacting with each other. The thesis is based on two extensive qualitative interview studies with politicians and senior civil servants, one carried out in the early 1980’s and one undertaken more recently. Hence it also offers an opportunity to analyse whether these expectations have changed or remained stable during the last decades. The findings reveal that the role expectations of politicians and civil servants to a high extent correspond, and have remained relatively stable over time. The relationship between politicians and civil servants is based on norms such as (conditional) trust, delegation and yet relatively close interaction. If so, politicians are unloaded by the civil service in order to handle their external responsibilities. Although relatively informal, a passive hierarchy of roles ensures the superiority of politicians and more specifically of the minister. Civil servants adapt to roles taken by politicians, although providing guidance to the politicians on how to behave in office. The division of labour is not based on the different tasks performed in the policy-making process. Instead, politicians assume responsibility for all actions and decisions – also those undertaken by the civil servants – within the ministries, while civil servants offer politicians protection and security. Taken together these results indicate that the institutionalised norms that surround the relationship between politicians and civil servants are highly powerful. Nevertheless, the thesis also reveals tendencies towards a departure from these norms, suggesting that this relationship is to some extent fragile and exposed to various attempts at reform.