The modern constitutional relationship between the British Crown and the Island dates from 1866 when an Act of Parliament was passed separating Manx revenues from those of the United Kingdom and giving the Island a limited measure of control over insular expenditure. Since then, a long series of measures, particularly over the last 40 years, has transferred control more and more into local hands. The Island remains a Crown Dependency but is now largely self-governing.
The Crown retains responsibility for the Island's defence and external relations (for which the Island makes an annual payment to the United Kingdom Government) and has ultimate responsibility for the good government of the Island. Westminster is empowered to legislate for the Island but, by convention, does not do so without the consent of the insular authorities. Primary legislation passed by the Island's own Parliament requires the Royal Assent before it can be given effect and the Crown appoints a Lieutenant Governor, two Deemsters (Judges) and the Island's Attorney General.
Any treaty or international agreement to which the United Kingdom Government becomes a party is not considered as applying automatically to the Island. Any such treaty or agreement may, however, expressly be applied to the Island, following consultation with the Island.
For more information visit the Isle of Man Government
Isle of Man Government