Chief of the Defence Staff (United Kingdom)
Chief of the Defence Staff is the title of the professional head of the British Armed Forces and the most senior uniformed military adviser to the Secretary of State for Defence and the prime minister of the United Kingdom, and also meets regularly with the monarch. The CDS is based at the Ministry of Defence and works alongside the Permanent Under-Secretary of State for Defence, the ministry's senior civil servant. The CDS is the highest-ranking officer to currently serve in the armed forces.
Constitutionally, the sovereign is the de jure commander-in-chief of the armed forces. However, in practice, the Government of the United Kingdom exercises the royal prerogative de facto and provides direction of the armed forces through the Ministry of Defence's Defence Council, of which the CDS is a member.
The current CDS is Air Chief Marshal Sir Rich Knighton, who succeeded Admiral Sir Tony Radakin in September 2025. Chiefs of the defence staff are appointed on the recommendation of the secretary of state for defence to the prime minister, before being approved by the monarch.
Responsibilities
The responsibilities of the CDS include:- commanding the service chiefs
- leading defence
- setting strategy for defence, including the future development of the Armed Forces
- the conduct of current operations
- leading relationships with other countries’ Armed Forces
Supporting and associated posts
The CDS is supported by a deputy, the Vice-Chief of the Defence Staff, who since 1997 has been of equivalent rank but is ordinarily from a different service to the CDS.There are also several Deputy Chief of the Defence Staff posts who support the VCDS. As of 2015, these are:
- Deputy Chief of Defence Staff
- Chief of Defence People
- Deputy Chief of Defence Staff for Military Capability
Additionally, the CDS is supported by a Strategic Advisory Panel.
History of the post
The post was created in 1959 to reflect the new concept of joint operations that had come to the fore in the Second World War. The first incumbent was Marshal of the RAF Sir William Dickson. Prior to the creation of the post, he had served as the chairman of the Chiefs of Staff Committee, from 1956 onwards. Before 1956, although no permanent post of chairman existed, the three service chiefs took it in turn to act as chairman at meetings. From the post's inception until the mid-to-late 1970s, CDS appointments were granted on a strict rotational basis between the three services. The first break in rotational order was precipitated by the death of Marshal of the RAF Sir Andrew Humphrey.From the creation of the post until 1997, the Chief of the Defence Staff was appointed to the highest rank in the respective branch of the British armed forces to which he belonged, being an admiral of the Fleet, a field marshal or marshal of the Royal Air Force,. However, with the post-Cold War reduction in the manpower strength of the British Armed Forces and the additional reasoning that no new "Five-star" appointments are to be made in peacetime, since 1997 the Chief of the Defence Staff has kept the rank of admiral, general or air chief marshal,, which he invariably already holds. However, during the 2010s Charles Guthrie, Michael Boyce, Michael Walker and Jock Stirrup were honorarily promoted to their respective services' senior ranks, sometime after they had each stepped down as CDS. Although there is no policy against a Royal Marines officer being appointed, few officers in the Corps attain a high enough rank to be considered for the post. However, in 2016, a Royal Marine officer Gordon Messenger was promoted to the rank of general and appointed as Vice-Chief of the Defence Staff. With the implementation of the Defence Reforms in April 2025, the CDS is also in charge of the Military Strategic Headquarters, commanding the four service chiefs and in charge of force design and equipment delivery to the armed forces. The CDS will also command the Deputy Chief of Defence Staff (Military Strategy & Operations) and the Deputy Chief of the Defence Staff.