King Charles has been announced as the ceremonial head of the Royal Marines on the 358th anniversary of the corps, taking over the role from Prince Harry.
The appointment of the ceremonial head of the Marines has historically been held by the Monarch – with His Majesty's grandfather and great-grandfather also having served in the role.
The Corps of Royal Marines, formed on 28 October 1664 during the reign of King Charles II, is widely acknowledged as one of the world's elite fighting forces.
In a personal message to the Royal Marines as they mark their 358th birthday today, the King said it was "the greatest possible pleasure to assume the role of your Captain General".
"I am exceptionally proud to follow in the footsteps of so many members of my family over the last three-and-a-half centuries, all of whom held the role with a deep sense of admiration.
Watch: Royal Marines test on-shore strike team capabilities in Cyprus.
"The Royal Marines have a distinguished and unparalleled history, both on land and at sea.
"I draw immense inspiration from your courage, determination, self-discipline and a remarkable capacity to endure in the most extreme environments.
"I feel greatly honoured to become part of the corps family and very much look forward to meeting many of you in the near future.
"In the meantime, this comes with my heartfelt and special wishes for a very happy 358th birthday.
"Per Mare, Per Terram," he added, quoting the Royal Marines motto which translates as 'By Land and by Sea'.
As Prince of Wales, King Charles enjoyed a career in the Royal Navy – including training at the Commando Training Centre Royal Marines (CTCRM) in Lympstone, Devon, to qualify as a helicopter pilot.
King Charles later served alongside Royal Marines on board HMS Hermes as part of 845 Naval Air Squadron – serving on military exercises in the Western Atlantic and the West Indies.
Harry was formally appointed the title by the Queen in 2017, assuming the role in succession to his grandfather, HRH the Duke of Edinburgh.
The Duke of Sussex held the title until February 2021 when he and his wife Meghan stepped down as senior Royals.
He also was stripped of other military appointments including Honorary Air Commandant of RAF Honington and Commodore-in-Chief of Small Ships and Diving, Royal Naval Command.