Ship of the line
A ship of the line was a type of naval warship constructed from the 17th through to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which depended on the two columns of opposing warships maneuvering to fire with the cannons along their broadsides. In conflicts where opposing ships were both able to fire from their broadsides, the side with more cannons, therefore more firepower had an advantage. Since these engagements were invariably won by the heaviest ships carrying the most powerful guns, the natural progression was to build sailing vessels that were the largest and most powerful of their time. From the end of the 1840s, the introduction of steam power brought less dependence on the wind in battle and led to the construction of screw-driven, wooden-hulled, ships of the line. However, the introduction of the ironclad frigate in about 1859 led swiftly to the decline of the steam-assisted ships of the line; the ironclad warship became the ancestor of the 20th-century battleship, whose designation is itself a contraction of the phrase "ship of the line of battle" or, more colloquially, "line-of-battle ship".
The term "ship of the line" has fallen into disuse except in historical contexts, after warships and naval tactics evolved and changed from the mid 19th century. The armed carrack, first developed in Portugal for either trade or war in the Atlantic Ocean, was the precursor of the ship of the line. Other maritime European states adopted it in the late 15th and early 16th centuries; these vessels were developed by fusing aspects of the cog of the North Sea and galley of the Mediterranean Sea. The cogs, which traded in the North Sea, in the Baltic Sea and along the Atlantic coasts, had an advantage over galleys in battle because they had raised platforms called "castles" at bow and stern that archers could occupy to fire down on enemy ships or to drop heavy weights from. Over time these castles became higher and larger, were built into the structure of the ship, increasing overall strength; this aspect of the cog remained in the newer-style carrack designs and proved its worth in battles like that at Diu in 1509.
The Mary Rose was an early 16th-century English carrack or "great ship". She was armed with 78 guns and 91 after an upgrade in the 1530s. Built in Portsmouth in 1510–1512, she was one of the earliest purpose-built men-of-war in the English navy, she was over 500 tons burthen, had a keel of over 32 m and a crew of over 200 sailors, 185 soldiers and 30 gunners. Although the pride of the English fleet, she accidentally sank during the Battle of the Solent, 19 July 1545. Henri Grâce à Dieu, nicknamed "Great Harry", was another early English carrack. Contemporary with Mary Rose, Henri Grâce à Dieu was 165 feet long, weighing 1,000–1,500 tons and having a complement of 700–1,000, it is said that she was ordered by Henry VIII in response to the Scottish ship Michael, launched in 1511. She was built at Woolwich Dockyard from 1512 to 1514 and was one of the first vessels to feature gunports and had twenty of the new heavy bronze cannon, allowing for a broadside. In all, she mounted 141 light guns, she was the first English two-decker, when launched she was the largest and most powerful warship in Europe, but she saw little action.
She was present at the Battle of the Solent against Francis I of France in 1545 but appears to have been more of a diplomatic vessel, sailing on occasion with sails of gold cloth. Indeed, the great ships were as well known for their ornamental design as they were for the power they possessed. Carracks fitted for war carried large-calibre guns aboard; because of their higher freeboard and greater load-bearing ability, this type of vessel was better suited than the galley to gunpowder weapons. Because of their development for conditions in the Atlantic, these ships were more weatherly than galleys and better suited to open waters; the lack of oars meant. Their disadvantage was that they were reliant on the wind for mobility. Galleys could still overwhelm great ships when there was little wind and they had a numerical advantage, but as great ships increased in size, galleys became less and less useful. Another detriment was the high forecastle, but as guns were introduced and gunfire replaced boarding as the primary means of naval combat during the 16th century, the medieval forecastle was no longer needed, ships such as the galleon had only a low, one-deck-high forecastle.
By the time of the 1637 launching of England's Sovereign of the Seas, the forecastle had disappeared altogether. During the 16th century the galleon evolved from the carrack, it was a more manoeuvrable type of ship with all the advantages of the carrack. The main ships of the English and Spanish fleets in the Battle of Gravelines of 1588 were galleons. By the 17th century every major European naval power was building ships like these. With the growing importance of colonies and exploration and the need to maintain trade routes across stormy oceans and galleasses were used
1942 Design Light Fleet Carrier
The 1942 Design Light Fleet Carrier referred to as the British Light Fleet Carrier, was a light aircraft carrier design created by the Royal Navy during the Second World War, used by eight naval forces between 1944 and 2001. They were designed and constructed by civilian shipyards to serve as an intermediate step between the expensive, full-size fleet aircraft carriers and the less expensive but limited-capability escort carriers. Sixteen Light Fleet carriers were ordered, all were laid down to the Colossus class design during 1942 and 1943. However, only eight were completed to this design. Two more were fitted with maintenance and repair facilities instead of aircraft catapults and arresting gear, entered service as aircraft maintenance carriers; the final six were modified during construction to handle larger and faster aircraft, were redesignated the Majestic class. The construction of the six ships was suspended at the end of the war. Five were completed with the last commissioning in 1961.
Although not completed in time to fight in the war, the carriers in Royal Navy service participated in the Korean War and the Suez Crisis. During the latter, two Colossus-class ships performed the first ship-based helicopter assault in history. Four Colossuses and all five completed Majestics were loaned or sold to seven foreign nations – Argentina, Brazil, France and the Netherlands – with three ships serving in three different naval forces during their careers. Foreign-operated Light Fleets took part in the Korean War, the First Indochina War, the Vietnam War, the 1971 Indo-Pakistani War, the Falklands War. Despite being intended as'disposable warships', all of the completed Light Fleet carriers exceeded their planned three-year service life; the maintenance carriers were the first to be paid off in the 1950s, by the 1960s, all of the Royal Navy carriers, had been sold to other nations or for ship breaking. The carriers in other navies had longer service lives. At the time of her decommissioning in 2001, Minas Gerais was the oldest active aircraft carrier in the world.
Despite attempts to preserve several of these carriers as museum ships, the last surviving example, was sold for scrapping in 2014. Experiences during the early part of the Second World War had demonstrated to the British that the Royal Navy needed access to defensive air cover for Allied fleets and convoys, which could only be provided by more aircraft carriers. In mid-1941, the Director of Naval Construction was instructed to investigate how best to achieve this without the lengthy construction times associated with carriers; the options were to refit the surviving Hawkins-class cruisers with flight decks and aviation facilities, convert additional merchant vessels and passenger liners into vessels similar to but more capable than previous merchant aircraft carriers, or create a new design for a cheap armed, unarmoured ship similar to the Woolworth carriers. In December 1941, it was decided; this ship was conceived as an intermediate step between the expensive fleet carriers and the limited-capability escort carriers.
The design had to be as simple as possible so construction time was kept to a minimum and so more shipyards could be used. However, the ships had to be capable of operating in fleet actions. Designated the'Intermediate Aircraft Carrier', the ships were reclassified as'Light Fleet Carriers'; because naval design staff were overworked, the carrier was designed by shipbuilders at Vickers-Armstrong. The Light Fleet design, completed at the start of 1942, was a scaled-down Illustrious; each carrier would displace 13,190 tons at standard load and 18,040 tons at full load, have a length of 680 feet at the flight deck and 695 feet overall, a maximum beam of 80 feet, a draught of 18 feet 6 inches at standard displacement, 23 feet 6 inches at full load displacement. The hull was built to Lloyd's specifications for merchant vessels from keel to maindeck, but incorporated better subdivision of compartments to reduce secondary damage by flooding; the propulsion machinery was of a similar design to that used in cruisers—some of the steam turbines were sourced from cancelled cruisers.
The machinery was arranged in two compartments, which were staggered en echelon, with the starboard compartment forward of the port. These provided 40,000 shaft horsepower to two propeller shafts, driving the carriers at a maximum speed of 25 knots, with 15 knots as the designated economical speed; the carriers were intended to be'disposable warships': to be scrapped and replaced at the end of the war or within three years of entering service. However, all exceeded this planned service life, with one ship operating from 1945 to 2001. Construction was approved by the Naval Board in February 1942, with the first two ships and Glory, laid down in March. During 1942 and 1943, another fourteen Light Fleet carriers were laid down under the 1942 Programme, to be constructed by eight British shipyards. Although it was planned that each Light Fleet would be ready for service in 21 months, modifications to the design saw the planned construction time increase to 27 months. With the omission of several important pieces of backup equipment, only two ships met this target.
Prince Consort-class ironclad
The Prince Consort class of battleship were four Royal Navy wooden-hulled broadside ironclads: HMS Royal Oak, HMS Prince Consort, HMS Ocean, HMS Caledonia. They were laid down as Bulwark-class battleships, but were converted to ironclads. Royal Oak was Britain's fifth ironclad battleship completed. Prince Consort and Caledonia were built to a common design and are today known as the Prince Consort class, though contemporaries knew them as the Caledonia class. Royal Oak was their half-sister; the Bulwark class of nine 91-gun two-decker steam line-of-battle ships were laid down between March 1859 and October 1860. Their dimensions were the same as HMS Duncan, but had a new timbering plan to suit the smaller armament; the reduction in armament was intended to improve the efficiency of the guns. Bulwark and Robust were suspended in March 1861 in an advanced state of construction and were broken up in March 1873 and August 1872 respectively; the remaining seven ships of the Bulwark class were less complete state and were converted into'ironclad frigates'.
Of these Triumph and Caledonia were converted to'broadside ironclads' with 1000 nhp engines. Royal Oak had a similar conversion but with the original 800 nhp engine. Royal Alfred and Repulse were converted into'central battery ships'; when the first British ironclads were conceived, the Surveyor said, "They must be regarded as an addition to our force, as a balance to those of France, not as calculated to supersede any existing class of ship. For this reason, the Royal Navy continued to lay down and complete steam two-deckers and three-deckers. However, in 1861, it was clear; the ten French ironclads laid down in 1861 were the start of the French programme of 1860, intended over a number of years to produce: 20 sea-going ironclads for the active fleet, 10 sea-going ironclads for the reserve fleet, 11 floating batteries. The British response to the French programme was taken in a number of steps. On 28 September 1860, the Board of Admiralty decided to order three new iron-hulled ironclads: one large - Achilles, two medium-size - Hector and Valiant.
Though there was still great uncertainty as to the value of ironclads, the Controller was directed to report as to their "fitness for use as transports or other duties in case it should be deemed advisable at any time to strip off their armour plates."On 7 February 1861 Rear Admiral Sir Baldwin Wake Walker resigned as Controller. He was replaced by Rear Admiral Sir Robert Spencer Robinson. Following a report from the British naval attaché in Paris regarding the progress of the French 1860 programme, the Naval members of the Board asked for the provision of ten new sea-going ironclads and the adaptation of ten or more existing steam line of battleships for armour protection with a total outlay of £3,000,000; the Prime Minister, Lord Palmerston, advocated cutting down and armouring the last sailing battleships rather than reducing the number of steam line of battleships. The Chancellor of the Exchequer, William Ewart Gladstone, had decided in November 1859 that ironclads must be the vessels of the future.
In early 1861, he was willing to accept a bigger appropriation for armoured ships if it could be offset by reduction in expenditure on wooden line of battleships. Gladstone suggested. In March 1861, construction of the Bulwark-class two-decker steam line of battleships was suspended. In May 1861 it was decided to convert the five least complete ships of the Bulwark class into ironclads, it was decided to lay down three new large iron-hulled ironclads, which became the Minotaur and Northumberland. Writing in December 1866, the Controller wrote: "The Caledonia and Ocean were ships of the line, of the largest class of two-deckers, in a certain state of advancement when in the Spring of 1861 I was appointed to the Controller’s office; the proposals I made in May 1861, to the Board, to convert these ships and three others into what they are now, was accepted, I beg leave to call their Lordships’ attention to the concluding paragraphs of those submissions which in substance were as follows - "'No doubt is entertained that the ship would be a sufficiently good sea boat to go to the Mediterranean, if required, that her speed would be at least as great as that estimated' -'but while proposing this mode of action I beg leave to observe that such ships will, in my opinion, be in every way inferior to ships of the Achilles class with those modifications which we propose to make in her Plating, but I have no hesitation in making these proposals, not as the wisest, not as the safest way of meeting the exigencies of the case, but because I am led to believe that other considerations make this plan the only practicable one.'
"I appeal with confidence to the Admiral’s reports as a proof that my expectation and those I held out to their Lordships in proposing these ships have been realized." "The two-decked wooden ship which were turned into armoured frigates had their sides cut down and the main deck and its battery removed. The iron-clad is, therefore
Landing Platform Helicopter
Landing Platform Helicopter is the hull classification used by a number of the world's navies to designate a type of amphibious warfare ship designed to operate as a launch and recovery platform for helicopters and other VTOL aircraft. As such, they are considered a type of helicopter carrier. Under the NATO Standardisation Agreement document for reporting vessels, LPH is a short form designator used for "Amphibious Assault Ship, Helicopter" defined as a "large helicopter carrier" for carrying and deploying around 1,800 assault troops using its own aircraft, but for which use of landing craft is "not a principal function". For ships of this hull classification in the Royal Navy, LPH is a direct acronym for "Landing Platform Helicopter", while the United States Navy referred to its vessels within this classification as "Amphibious Assault Ships". Regardless of the terminology, all vessels classified as an LPH possess similar capabilities; the Royal Navy used the term "Commando Carrier", which it applied to aircraft carriers converted to helicopter only operations.
The RN now operates one vessel that it classifies as HMS Ocean. Following the British government's decision to withdraw its Harrier aircraft at the end of 2010, the former light fleet carrier HMS Illustrious performed this role, but has now been decommissioned; the LPH classification was used by the United States Navy for the amphibious assault ships of the Iwo Jima class, a converted Casablanca-class escort carrier and three converted Essex-class aircraft carriers. No ships of this classification are in active service with the United States Navy, having been replaced with multi-purpose ships classified under NATO naming conventions as Landing Helicopter Dock or Landing Helicopter Assault ships. Royal Navy "Commando Carriers and "Amphibious Helicopter Carrier"s HMS Ocean – 1956 only, emergency minimal conversion for Suez Crisis Colossus-class aircraft carrier - Broken up HMS Theseus – 1956 only, emergency minimal conversion for Suez Crisis Colossus-class aircraft carrier - Broken up HMS Albion – 1962-1972, converted Centaur-class aircraft carrier - Converted to a Commando carrier in 1961/62.
Decommissioned 1972 and scrapped. HMS Bulwark – 1960-1980, converted Centaur-class aircraft carrier. Converted to an anti-submarine warfare carrier 1979. Damaged by a fire, she was not fit for emergency use in the Falklands War and was broken up. HMS Hermes – 1973-1976, converted Centaur-class aircraft carrier after which she was equipped as a helicopter anti-submarine warfare carrier and still as a Sea Harrier equipped VSTOL light carrier, which role continued after being sold to the Indian Navy. HMS Ocean – 1998-2018 designed and built as a commando carrier based on the Invincible-class STOVL carrier hull. Decommissioned in March 2018 and awaiting transfer to Brazil. HMS Illustrious - 2011-2014, Invincible-class aircraft carrier equipped and re-purposed as a commando carrier while HMS Ocean was in refit. Decommissioned in 2014 and scrapped in Turkey. USS Block Island – Commencement Bay-class escort carrier – Conversion to LPH cancelled -Scrapped USS Iwo Jima – Iwo Jima-class amphibious assault ship – First ship to be designed and built from the keel up as an amphibious assault ship - Scrapped USS Okinawa – Iwo Jima class - Sunk in SINKEX USS Boxer – Converted straight deck Essex-class aircraft carrier - Scrapped USS Princeton – Converted straight deck Essex-class aircraft carrier - Scrapped USS Thetis Bay – Minimal conversion of a Casablanca-class escort carrier - Scrapped USS Guadalcanal – Iwo Jima class - Sunk in SINKEX USS Valley Forge – Converted straight deck Essex-class aircraft carrier - Scrapped USS Guam – Iwo Jima class - Sunk in SINKEX USS Tripoli – Iwo Jima class – As of 10 September 2011, towed hulk still on loan to the US Army for launching targets for THAAD missiles at the Pacific Missile Range Facility.
USS New Orleans – Iwo Jima class - Sunk in SINKEX off of the coast of Oahu, Hawaii. USS Inchon – Iwo Jima class - Stricken from the list and sunk east of Virginia Beach, Virginia on 5 December 2004. Dokdo-class amphibious assault ship ROKS Dokdo ROKS Marado PHM Atlântico Amphibious assault ship Helicopter carrier List of amphibious warfare ships
The Royal Navy is the United Kingdom's naval warfare force. Although warships were used by the English kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years War against the Kingdom of France; the modern Royal Navy traces its origins to the early 16th century. From the middle decades of the 17th century, through the 18th century, the Royal Navy vied with the Dutch Navy and with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until surpassed by the United States Navy during the Second World War; the Royal Navy played a key part in establishing the British Empire as the unmatched world power during the 19th and first part of the 20th centuries. Due to this historical prominence, it is common among non-Britons, to refer to it as "the Royal Navy" without qualification. Following World War I, the Royal Navy was reduced in size, although at the onset of World War II it was still the world's largest.
By the end of the war, the United States Navy had emerged as the world's largest. During the Cold War, the Royal Navy transformed into a anti-submarine force, hunting for Soviet submarines and active in the GIUK gap. Following the collapse of the Soviet Union, its focus has returned to expeditionary operations around the world and remains one of the world's foremost blue-water navies. However, 21st century reductions in naval spending have led to a personnel shortage and a reduction in the number of warships; the Royal Navy maintains a fleet of technologically sophisticated ships and submarines including two aircraft carriers, two amphibious transport docks, four ballistic missile submarines, six nuclear fleet submarines, six guided missile destroyers, 13 frigates, 13 mine-countermeasure vessels and 22 patrol vessels. As of November 2018, there are 74 commissioned ships in the Royal Navy, plus 12 ships of the Royal Fleet Auxiliary; the RFA replenishes Royal Navy warships at sea, augments the Royal Navy's amphibious warfare capabilities through its three Bay-class landing ship vessels.
It works as a force multiplier for the Royal Navy doing patrols that frigates used to do. The total displacement of the Royal Navy is 408,750 tonnes; the Royal Navy is part of Her Majesty's Naval Service, which includes the Royal Marines. The professional head of the Naval Service is the First Sea Lord, an admiral 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 three bases in the United Kingdom; as the seaborne branch of HM Armed Forces, the RN has various roles. As it stands today, the RN has stated its 6 major roles as detailed below in umbrella terms. 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 Maintaining a Readiness To Fight – To protect the United Kingdom's interests across the globe Protecting the Economy – To safe guard 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 strength of the fleet of the Kingdom of England was an important element in the kingdom's power in the 10th century.
At one point Aethelred II had an large fleet built by a national levy of one ship for every 310 hides of land, but it is uncertain whether this was a standard or exceptional model for raising fleets. During the period of Danish rule in the 11th century, the authorities maintained a standing fleet by taxation, this continued for a time under the restored English regime of Edward the Confessor, who commanded fleets in person. English naval power declined as a result of the Norman conquest. Following the Battle of Hastings, the Norman navy that brought over William the Conqueror disappeared from records due to William receiving all of those ships from feudal obligations or because of some sort of leasing agreement which lasted only for the duration of the enterprise. More troubling, is the fact that there is no evidence that William adopted or kept the Anglo-Saxon ship mustering system, known as the scipfryd. Hardly noted after 1066, it appears that the Normans let the scipfryd languish so that by 1086, when the Doomsday Book was completed, it had ceased to exist.
According to the Anglo-Saxon Chronicle, in 1068, Harold Godwinson's sons Godwine and Edmund conducted a ‘raiding-ship army’ which came from Ireland, raiding across the region and to the townships of Bristol and Somerset. In the following year of 1069, they returned with a bigger fleet which they sailed up the River Taw before being beaten back by a local earl near Devon. However, this made explicitly clear that the newly conquered England under Norman rule, in effect, ceded the Irish Sea to the Irish, the Vikings of Dublin, other Norwegians. Besides ceding away the Irish Sea, the Normans ceded the North Sea, a major area where Nordic peoples traveled. In 1069, this lack of naval presence in the North Sea allowed for the invasion an
HMS Ocean (1862)
HMS Ocean was the last of the Royal Navy's four Prince Consort-class ironclads to be completed in the mid-1860s. She was laid down as a 91-gun second-rate ship of the line, was converted during construction to an armoured frigate; the ship served as flagship there for a time. Upon her return to Great Britain in 1872 her hull was found to be rotten and she was placed in reserve until she was sold for scrap in 1882. HMS Ocean had a beam of 58 feet 5 inches; the ship had 27 feet 6 inches aft. She displaced 6,832 long tons. Ocean had a metacentric height of 6.01 feet which meant that she rolled a lot and was an unsteady gun platform. Her hull was sheathed with Muntz metal to reduce biofouling, her crew enlisted men. Ocean had a simple horizontal 2-cylinder horizontal return connecting-rod steam engine driving a single propeller shaft using steam was provided by eight rectangular boilers; the engine produced 4,244 indicated horsepower during the ship's sea trials in June 1864 which gave the ship a maximum speed of 12.9 knots.
Ocean carried a maximum of 570 long tons of coal, enough to steam 2,000 nautical miles at 5 knots. She had a sail area of 25,000 square feet, her best speed with the propeller disconnected and under sail alone was 11.5 knots. Yards were added to the ship's mizzenmast by 1866 and Ocean was given a full ship rig which she retained for the rest of her career. Ocean was armed with twenty-four seven-inch rifled muzzle-loading guns. Four of these guns were mounted on the upper deck as two each fore and aft; the 16-calibre seven-inch gun fired a 112-pound shell. It was credited with the ability to penetrate 7.7 inches of armour. In 1867 four of these guns were replaced by eight-inch rifled muzzle-loaders; the shell of the 15-calibre eight-inch gun weighed 175 pounds while the gun itself weighed nine long tons. It had a muzzle velocity of 1,410 ft/s and was credited with the ability to penetrate 9.6 inches of wrought iron armour at the muzzle. The entire side of the Prince Consort-class ships, from the upper-deck level downwards, was protected by wrought iron armour that tapered from 3 inches at the ends to 4.5 inches amidships.
The armour extended 5 feet 6 inches below the waterline. One small conning tower was fitted on each side of the upper deck amidships, but these proved to be untenable when the ship's guns were fired; the armour was backed by the sides of the ship. HMS Ocean was laid down on 23 August 1860 as a wooden two-deck, 90-gun ship of the line by Devonport Dockyard; the Admiralty ordered on 5 June 1861 that she be lengthened 23 feet, cut down one deck, converted to an armoured frigate for the price of £298,851. The ship was launched on 19 March 1863 and commissioned in July 1866, but was not completed until 6 September 1866. Ocean served with the Channel Fleet, but she was immediately transferred to the Mediterranean, from there to the Far East, she was the only armoured ship to double the Cape of Good Hope under canvas alone. During this voyage Ocean set a record in having sailed 243 nautical miles on 26 August 1867 with cold boilers, the greatest distance covered under sail power by a British ironclad.
Ocean served on the China Station without docking once. The ship relieved the old two-decker HMS Rodney as station flagship in 1869 when Vice-Admiral Henry Kellett took command. Ocean was relieved in turn by HMS Iron Duke in 1872, but drew too much water to pass through the Suez Canal; the Admiralty therefore ordered. The ship's bottom was foul and she averaged only 4.5 knots during the voyage. Ocean had lost a lot of sheathing during her time in the Far East and much of her planking was in a bad state; the ship was therefore relegated to dockyard reserve until sold in 1882. Ballard, G. A. Admiral; the Black Battlefleet. Annapolis, MD: Naval Institute Press. ISBN 0-87021-924-3. Gardiner, Robert, ed.. Conway's All the World's Fighting Ships 1860–1905. Greenwich: Conway Maritime Press. ISBN 0-8317-0302-4. Parkes, Oscar. British Battleships. Annapolis, MD: Naval Institute Press. ISBN 1-55750-075-4. Silverstone, Paul H.. Directory of the World's Capital Ships. New York: Hippocrene Books. ISBN 0-88254-979-0
The Korean War was a war between North Korea and South Korea. The war began on 25 June 1950 when North Korea invaded South Korea following a series of clashes along the border; as a product of the Cold War between the Soviet Union and the United States, Korea had been split into two sovereign states in 1948. A socialist state was established in the north under the communist leadership of Kim Il-sung and a capitalist state in the south under the anti-communist leadership of Syngman Rhee. Both governments of the two new Korean states claimed to be the sole legitimate government of all of Korea, neither accepted the border as permanent; the conflict escalated into warfare when North Korean military forces—supported by the Soviet Union and China—crossed the border and advanced south into South Korea on 25 June 1950. The United Nations Security Council authorized the formation and dispatch of UN forces to Korea to repel what was recognized as a North Korean invasion. Twenty-one countries of the United Nations contributed to the UN force, with the United States providing around 90% of the military personnel.
After the first two months of war, South Korean and U. S. forces dispatched to Korea were on the point of defeat, forced back to a small area in the south known as the Pusan Perimeter. In September 1950, an amphibious UN counter-offensive was launched at Incheon, cut off many North Korean troops; those who escaped envelopment and capture were forced back north. UN forces approached the Yalu River—the border with China—but in October 1950, mass Chinese forces crossed the Yalu and entered the war; the surprise Chinese intervention triggered a retreat of UN forces which continued until mid-1951. In these reversals of fortune, Seoul changed hands four times, the last two years of fighting became a war of attrition, with the front line close to the 38th parallel; the war in the air, was never a stalemate. North Korea was subject to a massive bombing campaign. Jet fighters confronted each other in air-to-air combat for the first time in history, Soviet pilots covertly flew in defense of their communist allies.
The fighting ended on 27 July 1953. The agreement created the Korean Demilitarized Zone to separate North and South Korea, allowed the return of prisoners. However, no peace treaty was signed, according to some sources the two Koreas are technically still at war, engaged in a frozen conflict. In April 2018, the leaders of North and South Korea met at the demilitarized zone and agreed to work towards a treaty to formally end the Korean War. In South Korea, the war is referred to as "625" or the "6–2–5 Upheaval", reflecting the date of its commencement on June 25. In North Korea, the war is referred to as the "Fatherland Liberation War" or alternatively the "Chosǒn War". In China, the war is called the "War to Resist America and Aid Korea", although the term "Chaoxian War" is used in unofficial contexts, along with the term "Hán War" more used in regions such as Hong Kong and Macau. In the U. S. the war was described by President Harry S. Truman as a "police action" as the United States never formally declared war on its opponents and the operation was conducted under the auspices of the United Nations.
It has been referred to in the English-speaking world as "The Forgotten War" or "The Unknown War" because of the lack of public attention it received both during and after the war, in relation to the global scale of World War II, which preceded it, the subsequent angst of the Vietnam War, which succeeded it. Imperial Japan destroyed the influence of China over Korea in the First Sino-Japanese War, ushering in the short-lived Korean Empire. A decade after defeating Imperial Russia in the Russo-Japanese War, Japan made Korea its protectorate with the Eulsa Treaty in 1905 annexed it with the Japan–Korea Annexation Treaty in 1910. Many Korean nationalists fled the country; the Provisional Government of the Republic of Korea was founded in 1919 in Nationalist China. It failed to achieve international recognition, failed to unite nationalist groups, had a fractious relationship with its U. S.-based founding president, Syngman Rhee. From 1919 to 1925 and beyond, Korean communists led internal and external warfare against the Japanese.
In China, the Nationalist National Revolutionary Army and the communist People's Liberation Army helped organize Korean refugees against the Japanese military, which had occupied parts of China. The Nationalist-backed Koreans, led by Yi Pom-Sok, fought in the Burma Campaign; the communists, led by Kim Il-sung among others, fought the Japanese in Manchuria. At the Cairo Conference in November 1943, the United Kingdom, the United States all decided that "in due course Korea shall become free and independent". At the Tehran Conference in November 1943 and the Yalta Conference in February 1945, the Soviet Union promised to join its allies in the Pacific War within three months of the victory in Europe. Accordingly, it declared war o