This chapter discusses the legal and political history of the main cities of the Low Countries. It argues that the middling sort of people had an influential voice in the creation and maintenance of urban political institutions. Their struggle for power was not a conservative effort to maintain privileges, as many have characterised medieval and early modern popular protest. Rather, the urban ‘commoners’ (as they called themselves) fought for new privileges which would give them corporate autonomy and rights of political participation. The chapter also deals with the political ideas of citizens. The urban governors identified themselves with a perhaps idealised urban community, in which rulers acted for the common interest (the ‘bien commun’) of every citizen, although there was vehement discussion over whose particular interests were truly ‘common’.