The Royal Navy (RN) is the naval warfare force of the United Kingdom, responsible for defending the country, the Crown Dependencies, and the Overseas Territories from naval attack or invasion. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the English Navy of the early 16th century, making it the oldest of the United Kingdom's armed services. It is consequently known as the Senior Service.
From the early 18th century until the Second World War, it was the world's most powerful navy. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superiority. Following World War I, it was significantly reduced in size.Rose, Power at Sea, p. 36 During the Cold War, the Royal Navy transformed into a primarily anti-submarine force, hunting for Soviet submarines and mostly active in the GIUK gap. Following the collapse of the Soviet Union, its focus returned to expeditionary operations.Hyde-Price, European Security, pp. 105–106.
The Royal Navy maintains a fleet of technologically sophisticated ships, submarines, and aircraft, including two Queen Elizabeth-class aircraft carriers, four Vanguard-class ballistic missile submarines (which carry the Trident strategic nuclear weapons), six Astute-class nuclear-powered attack submarines, six Type 45 guided missile destroyers, five Type 23 frigates, seven mine-countermeasure vessels and twenty-six patrol vessels. As of July 2026, there are 60 active and commissioned ships (including submarines as well as one historic ship, ) in the Royal Navy, plus 9 ships of the Royal Fleet Auxiliary (RFA). There are also four Point-class sealift ships from the Merchant Navy available to the RFA under a private finance initiative, while the civilian Marine Services operate auxiliary vessels which further support the Royal Navy in various capacities.
The Royal Navy is part of His Majesty's Naval Service, which also includes the Royal Marines and the Royal Fleet Auxiliary. The professional head of the Naval Service is the First Sea Lord who is a general and member of the Defence Council of the United Kingdom. The Defence Council delegates management of the Naval Service to the Admiralty Board, chaired by the secretary of state for defence. The Royal Navy operates from three bases in Britain where commissioned ships and submarines are based: Portsmouth, Clyde and Devonport, the last being the largest operational naval base in Western Europe, as well as two naval air stations, RNAS Yeovilton and RNAS Culdrose where maritime aircraft are based.
Role The Royal Navy stated its six major roles in umbrella terms in 2017 as: Preventing Conflict – On a global and regional level Providing Security At Sea – To ensure the stability of international trade at sea International Partnerships – To help cement the relationship with the United Kingdom's allies (such as NATO) Maintaining a Readiness To Fight – To protect the United Kingdom's interests across the globe Protecting the Economy – To safeguard vital trade routes to guarantee the United Kingdom's and its allies' economic prosperity at sea Providing Humanitarian Aid – To deliver a fast and effective response to global catastrophes
The Royal Navy protects British interests at home and abroad, executing the foreign and defence policies of His Majesty's Government through the exercise of military effect, diplomatic activities and other activities in support of these objectives. It is also a key element of the British contribution to NATO, with several ships or aircraft allocated to NATO tasks at any time. In 2007 core capabilities were described as: Maintenance of the UK Nuclear Deterrent through a policy of Continuous at Sea Deterrence Provision of two medium-scale maritime task groups with the Fleet Air Arm Delivery of the UK Commando force Contribution of assets to the Joint Aviation Command Maintenance of standing patrol commitments Provision of mine counter measures capability to United Kingdom and allied commitments Provision of hydrographic and meteorological services deployable worldwide Protection of Britain's Exclusive Economic Zone
History
The English Royal Navy was formally founded in 1546 by Henry VIII, though the Kingdom of England had possessed less-organised naval forces for centuries prior to this.
The Royal Scots Navy (or Old Scots Navy) had its origins in the Middle Ages until its merger with the English Royal Navy per the Acts of Union 1707.S. Murdoch, The Terror of the Seas?: Scottish Maritime Warfare, 1513–1713 (Leiden: Brill, 2010), , p. 10.
Earlier fleets
During much of the medieval period, fleets or "king's ships" were often established or gathered for specific campaigns or actions, and these would disperse afterwards. These were generally merchant ships enlisted into service. Unlike some European states, England did not maintain a small permanent core of warships in peacetime. England's naval organisation was haphazard and the mobilisation of fleets when war broke out was slow.Rodger, Safeguard, pp. 52–53, 117–130. Control of the sea only became critical to Anglo-Saxon kings in the 10th century. In the 11th century, Æthelred the Unready had a large fleet built by a national levy.Swanton, p. 138. During the period of Danish rule in the 11th century, authorities maintained a standing fleet by taxation, and this continued for a time under Edward the Confessor, who frequently commanded fleets in person.Swanton, pp. 154–165, 160–172. After the Norman Conquest in 1066, English naval power waned and England suffered large naval raids from the Vikings. In 1069, this allowed for the invasion and ravaging of England by Jarl Osborn, brother of King Svein Estridsson, and his sons.
The lack of an organised navy came to a head during the First Barons' War, in which Prince Louis of France invaded England in support of northern barons. With King John unable to organise a navy, this meant the French landed at Sandwich unopposed in April 1216. John's flight to Winchester and his death later that year left William Marshal, 1st Earl of Pembroke as regent, and he was able to marshal ships to fight the French in the Battle of Sandwich in 1217 – one of the first major English battles at sea. The outbreak of the Hundred Years War emphasised the need for an English fleet. French plans for an invasion of England failed when Edward III of England destroyed the French fleet in the Battle of Sluys in 1340.Rodger, Safeguard, pp. 93–99. England's naval forces could not prevent frequent raids on the south-coast ports by the French and their allies. Such raids halted only with the occupation of northern France by Henry V.Rodger, Safeguard, pp. 91–97, 99–116, 143–144.
A Scottish fleet existed by the reign of William the Lion in the late 12th century.P. F. Tytler, History of Scotland, Volume 2 (London: Black, 1829), pp. 309–310. In the early 13th century there was a resurgence of Viking naval power in the region. The Vikings clashed with Scotland over control of the islesP. J. Potter, Gothic Kings of Britain: the Lives of 31 Medieval Rulers, 1016–1399 (Jefferson, NC: McFarland, 2008), , p. 157. though Alexander III was ultimately successful in asserting Scottish control.A. Macquarrie, Medieval Scotland: Kinship and Nation (Thrupp: Sutton, 2004), , p. 153. The Scottish fleet was of particular import in repulsing English forces in the early 14th century.N. A. M. Rodger, The Safeguard of the Sea: A Naval History of Britain. Volume One 660–1649 (London: Harper, 1997) pp. 74–90.
Age of Sail
A standing "Navy Royal", with its own secretariat, dockyards and a permanent core of purpose-built warships, emerged during the reign of Henry VIII.Rodger, Safeguard, pp. 221–237. Under Elizabeth I, England became involved in a war with Spain, which saw privately owned vessels combining with the Queen's ships in highly profitable raids against Spanish commerce and colonies.Rodger, Safeguard, pp. 238–253, 281–286, 292–296. The Royal Navy was then used in 1588 to repulse the Spanish Armada, but the English Armada was lost the next year. In 1603, the Union of the Crowns created a personal union between England and Scotland. While the two remained distinct sovereign states for a further century, the two navies increasingly fought as a single force. During the early 17th century, England's relative naval power deteriorated until Charles I undertook a major programme of shipbuilding. His methods of financing the fleet contributed to the outbreak of the English Civil War, and the abolition of the monarchy.Rodger, Safeguard, pp. 379–394, 482.
The Commonwealth of England replaced many names and symbols in the new Commonwealth Navy, associated with royalty and the high church, and expanded it to become the most powerful in the world.John Barratt, 2006, Cromwell's Wars at Sea. Barnsley, South Yorkshire; Pen & Sword; pp.Rodger, Command, pp. 2–3, 216–217, 607. The fleet was quickly tested in the First Anglo-Dutch War (1652–1654) and the Anglo-Spanish War (1654–1660), which saw the British conquest of Jamaica and successful attacks on Spanish treasure fleets. The 1660 Restoration saw Charles II rename the Royal Navy again, and started use of the prefix HMS. The Navy remained a national institution and not a possession of the Crown as it had been before. Following the Glorious Revolution of 1688, England joined the War of the Grand Alliance which marked the end of France's brief pre-eminence at sea and the beginning of an enduring British supremacy which would help with the creation of the British Empire.Rodger, Command, pp. 142–152, 607–608.