General Sir Gwyn Jenkins KCB OBE ADC RM
First Sea Lord and Chief of the Naval Staff,
Royal Navy
United Kingdom
General Gwyn commissioned into the Royal Marines in 1990. His time as a junior officer was spent in the Commando Logistics Regiment, competing for the Royal Navy and Royal
Marines in cross-country skiing and on operations in Northern Ireland with 42 Commando RM.
A graduate of the Advanced Command and Staff Course at the Military College Shrivenham, where he completed a master’s degree in Defence Studies in 2004, he went on to serve as a Lieutenant Colonel overseeing global operations in PJHQ, before a Commanding Officer appointment in 2009. On completion of his command tour, he was promoted to Colonel and deployed for 12 months to Afghanistan, for which he was awarded an OBE, returning to the UK in 2012 as the Military Assistant to the Prime Minister in No 10 Downing Street.
After two years in No. 10, he completed the Higher Command and Staff Course, was promoted to Brigadier, and took up a 3* civilian appointment in the Cabinet Office as Deputy National Security Advisor for Conflict, Stability and Defence. In April 2017 he moved back to the military and took command of 3 Commando Brigade, conducting exercises and overseeing operational deployments around the world. He was promoted to Major General in January 2019, in which rank he served first in the Royal Navy as the Assistant Chief of Naval Staff and subsequently commanded a tri-service organisation.
In August 2022 he was appointed the Vice Chief of the Defence Staff and promoted to General. In November 2022, General Gwyn was appointed Commandant General of the
Royal Marines. In August 2024, General Gwyn was made a Strategic Advisor to the Secretary of State for Defence. In this role, he has negotiated the UK’s Defence Agreement with Germany and cohered the UK’s strategic partnership with Norway.
In May 2025 he became the first Royal Marine to be appointed to his current role as First Sea Lord and Chief of Naval Staff. He lives with his wife and children and enjoys a range
of activities including sailing, skiing, and creative writing.
Marines in cross-country skiing and on operations in Northern Ireland with 42 Commando RM.
A graduate of the Advanced Command and Staff Course at the Military College Shrivenham, where he completed a master’s degree in Defence Studies in 2004, he went on to serve as a Lieutenant Colonel overseeing global operations in PJHQ, before a Commanding Officer appointment in 2009. On completion of his command tour, he was promoted to Colonel and deployed for 12 months to Afghanistan, for which he was awarded an OBE, returning to the UK in 2012 as the Military Assistant to the Prime Minister in No 10 Downing Street.
After two years in No. 10, he completed the Higher Command and Staff Course, was promoted to Brigadier, and took up a 3* civilian appointment in the Cabinet Office as Deputy National Security Advisor for Conflict, Stability and Defence. In April 2017 he moved back to the military and took command of 3 Commando Brigade, conducting exercises and overseeing operational deployments around the world. He was promoted to Major General in January 2019, in which rank he served first in the Royal Navy as the Assistant Chief of Naval Staff and subsequently commanded a tri-service organisation.
In August 2022 he was appointed the Vice Chief of the Defence Staff and promoted to General. In November 2022, General Gwyn was appointed Commandant General of the
Royal Marines. In August 2024, General Gwyn was made a Strategic Advisor to the Secretary of State for Defence. In this role, he has negotiated the UK’s Defence Agreement with Germany and cohered the UK’s strategic partnership with Norway.
In May 2025 he became the first Royal Marine to be appointed to his current role as First Sea Lord and Chief of Naval Staff. He lives with his wife and children and enjoys a range
of activities including sailing, skiing, and creative writing.
Sessions
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09-Sep-2025Cyber & Specialist Operations Command (CSOC) Keynote ForumDSEI UK 2025 KEYNOTE - The Royal Navy - Read to Warfight Now


