King Charles will take over as Captain General of the Royal Marines, a post previously held by his son Prince Harry, who stepped back from royal duties in March 2020.
MORE: Viewers heap praise on King Charles after 'enchanting' Repair Shop appearance
On Friday, Buckingham Palace made the announcement on the 358th anniversary of the founding of the Corps of Royal Marines, which was formed on 28th October 1664 during the reign of King Charles II.
WATCH: King Charles treated to royal tradition for first time
Widely acknowledged as one of the world's elite fighting forces, the Royal Marine Commandos are the amphibious troops of the Royal Navy. They are deployed across the globe as specialists in combat in extreme climates, serving on the most dangerous operations under the most challenging conditions.
MORE: King Charles has a very special wish for his granddaughter Princess Charlotte
READ: King Charles III sells beloved racehorses inherited from the Queen
The appointment of the ceremonial head of the Royal Marines has historically been held by the Monarch, including the King's grandfather and great-grandfather.
In a personal message to the Royal Marines as they mark their 358th birthday today, The King said: "It is 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.
Prince Harry was previously the Captain General Royal Marines
"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."
The King embarked on a career in the Royal Navy, undergoing training at the Commando Training Centre Royal Marines (CTCRM) in Lympstone, Devon, in order to qualify as a helicopter pilot. The monarch later served alongside Royal Marines on board HMS Hermes, as part of 845 Naval Air Squadron, completing military exercises in the Western Atlantic and the West Indies.
It was previously tipped that the late Queen's only daughter would be following in the footsteps of her late father, the Duke of Edinburgh, who held the role of Captain General of the Royal Marines for 64 years until 2017. The Princess is patron of the Royal Navy and Royal Marines Charity as well as being Commodore-in-Chief for Portsmouth.