According to their charters, borough magistrates were to be independent of county justices of the peace. But between 1664 and 1688, the crown granted commissions of association appointing county justices to act in twenty-one towns. Though such commissions effectively annulled provisions in corporate charters, their use was entirely within the law of franchises by which such charters were granted. Three phases mark the life of these commissions: the mid-1660s, when the gentry – not the crown – prompted their use for their own purposes; the late 1660s to 1670s, when the crown used them to strengthen excise collection; and the 1680s, when they were used to support a more ambitious policy of imposing new charters on the corporations. Their use thus reveals when, how, and why the relationship between royal and local authorities changed, demonstrating the crown's essentially benign posture toward the provinces in the 1660s and 70s, thereby providing a vivid contrast to developments in the 1680s.