Counsellors of State are senior members of the British royal family to whom the monarch can delegate royal functions through letters patent under the Great Seal, to prevent delay or difficulty in the dispatch of public business in the case of their illness (except total incapacity) or of their intended or actual absence from the United Kingdom.
Counsellors of state may carry out "such of the royal functions as may be specified in the Letters Patent". In practice, this means most of the monarch's official duties, such as attending Privy Council meetings, signing routine documents and receiving the credentials of new ambassadors to the Court of St James's. However, by law, counsellors of state cannot grant ranks, titles or peerages. They also, by the terms of the letters patent, cannot deal with a number of core constitutional functions, such as Commonwealth matters, the dissolution of Parliament (except on the monarch's express instruction) and the appointment of prime ministers. A rare example occurred on 7 February 1974 of the Proclamation of the Dissolution of Parliament being promulgated by Queen Elizabeth The Queen Mother and Princess Margaret as counsellors of state, on the express instructions of Queen Elizabeth II.
