"My life will of course change as I take up my new responsibilities," the King said.

The ruler said that while it will no longer be possible for him to give his time and energy to the charities and issues for which he "cared so deeply", he is certain that the "important work will go on in the trusted hands of others".

"This is also a time of change for my family. I count on the loving help of my darling wife Camilla. In recognition of her own loyal public service since our marriage 17 years ago, she becomes my Queen Consort," the King announced.

"I know she will bring to the demands of her new role the steadfast devotion to duty on which I have come to rely so much," he added.