English Channel in the context of "Celtic Sea"

France, officially the French Republic, is a country primarily located in Western Europe. Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the North Atlantic, the French West Indies, and many islands in Oceania and the Indian Ocean, giving it the largest discontiguous exclusive economic zone in the world. Metropolitan France shares borders with Belgium and Luxembourg to the north; Germany to the northeast; Switzerland to the east; Italy and Monaco to the southeast; Andorra and Spain to the south; and a maritime border with the United Kingdom to the northwest. Its metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea. Its 18 integral regions—five of which are overseas—span a combined area of 632,702 km (244,288 sq mi) and have an estimated total population of over 68.6 million as of January 2025. France is a semi-presidential republic. Its capital, largest city and main cultural and economic centre is Paris.

Metropolitan France was settled during the Iron Age by Celtic tribes known as Gauls before Rome annexed the area in 51 BC, leading to a distinct Gallo-Roman culture. In the Early Middle Ages, the Franks formed the kingdom of Francia, which became the heartland of the Carolingian Empire. The Treaty of Verdun of 843 partitioned the empire, with West Francia evolving into the Kingdom of France. In the High Middle Ages, France was a powerful but decentralised feudal kingdom, but from the mid-14th to the mid-15th centuries, France was plunged into a dynastic conflict with England known as the Hundred Years' War. In the 16th century French culture flourished during the French Renaissance, and a French colonial empire emerged. Internally, France was dominated by the conflict with the House of Habsburg and the French Wars of Religion between Catholics and Huguenots. France was successful in the Thirty Years' War and further increased its influence during the reign of Louis XIV.

England is a country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and more than 100 smaller adjacent islands. England shares a land border with Scotland to the north and another land border with Wales to the west, and is otherwise surrounded by the North Sea to the east, the English Channel to the south, the Celtic Sea to the south-west, and the Irish Sea to the west. Continental Europe lies to the south-east, and Ireland to the west. At the 2021 census, the population was 56,490,048. London is both the largest city and the capital.

The area now called England was first inhabited by modern humans during the Upper Paleolithic. It takes its name from the Angles, a Germanic tribe who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had extensive cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The Kingdom of England, which included Wales after 1535, ceased to be a separate sovereign state on 1 May 1707, when the Acts of Union brought into effect a political union with the Kingdom of Scotland that created the Kingdom of Great Britain.

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland, with a population of over 69 million in 2024. The UK includes the island of Great Britain, the north-eastern part of the island of Ireland, and most of the smaller islands within the British Isles, covering 94,354 square miles (244,376 km). It shares a land border with the Republic of Ireland and is otherwise surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea, while maintaining sovereignty over the British Overseas Territories. The capital and largest city of both England and the UK is London; Edinburgh, Cardiff and Belfast are the national capitals of Scotland, Wales and Northern Ireland.

Britain has been inhabited since the Neolithic. In AD 43 the Roman conquest of Britain began. The Roman departure between 383 and 410 was followed by Anglo-Saxon settlement beginning around 450. In 1066 the Normans conquered England. After the Wars of the Roses, the Kingdom of England began to flourish, resulting in the 16th-century annexation of Wales and the establishment of the British Empire. Over the 17th century the role of the British monarchy was reduced, particularly as a result of the English Civil War. In 1707 the Kingdom of England and the Kingdom of Scotland united under the Treaty of Union to create the Kingdom of Great Britain. In the Georgian era the office of prime minister became established. The Acts of Union 1800 incorporated the Kingdom of Ireland to create the United Kingdom of Great Britain and Ireland in 1801. Most of Ireland seceded from the UK in 1922 as the Irish Free State, and the Royal and Parliamentary Titles Act 1927 created the present United Kingdom.

The Battle of Britain (German: Luftschlacht um England, lit. 'air battle for England') was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defended the United Kingdom against large-scale attacks by Nazi Germany's air force, the Luftwaffe. It was the first major military campaign fought entirely by air forces. It takes its name from the speech given by Prime Minister Winston Churchill to the House of Commons on 18 June, 1940: "What General Weygand called the 'Battle of France' is over. I expect that the Battle of Britain is about to begin."

The Germans had rapidly overwhelmed France and the Low Countries in the Battle of France, leaving Britain to face the threat of invasion by sea. The German high command recognised the difficulties of a seaborne attack while the Royal Navy controlled the English Channel and the North Sea. The primary objective of the German forces was to compel Britain to agree to a negotiated peace settlement.

East Sussex is a ceremonial county in South East England. It is bordered by Kent to the north-east, West Sussex to the west, Surrey to the north-west, and the English Channel to the south. The largest settlement is the city of Brighton and Hove.

The county has an area of 1,792 km (692 sq mi) and had an estimated population of 844,752 in 2024. The largest settlements are located on the coast, and include Brighton and Hove in the south west, Eastbourne in the south, and Hastings in the south east. Away from the coast the county is largely rural, and its major settlements include Crowborough in the north, Halisham in the south-centre, and Lewes in the west. For local government purposes East Sussex comprises a non-metropolitan county, with five districts, and the unitary authority area of Brighton and Hove. East Sussex and West Sussex historically formed a single county, Sussex.

World War I, or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a global conflict between two coalitions: the Allies (or Entente) and the Central Powers. Major areas of conflict included Europe and the Middle East, as well as parts of Africa and the Asia-Pacific. The war saw important developments in weaponry including tanks, aircraft, artillery, machine guns, and chemical weapons. One of the deadliest conflicts in history, it resulted in an estimated 30 million military casualties, and 8 million civilian deaths from war-related causes and genocide. The movement of large numbers of people was a major factor in the deadly Spanish flu pandemic.

The causes of World War I included the rise of the German Empire and decline of the Ottoman Empire, which disturbed the long-standing balance of power in Europe, the exacerbation of imperial rivalries, and an arms race between the great powers. Growing tensions in the Balkans reached a breaking point on 28 June 1914 when Gavrilo Princip, a Bosnian Serb, assassinated Franz Ferdinand, the heir to the Austro-Hungarian throne. Austria-Hungary blamed Serbia, and declared war on 28 July. After Russia mobilised in Serbia's defence, Germany declared war on Russia and France, who had an alliance. The United Kingdom entered the war after Germany invaded Belgium, and the Ottoman Empire joined the Central Powers in November. Germany's strategy in 1914 was to quickly defeat France before transferring its forces to the east, but its advance was halted in September, and by the end of the year the Western Front consisted of a near-continuous line of trenches from the English Channel to Switzerland. The Eastern Front was more dynamic, but neither side gained a decisive advantage, despite costly offensives. Italy, Bulgaria, Romania, Greece and others entered the war from 1915 onward.

The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, covering 570,000 square kilometres (220,000 sq mi).

It hosts key north European shipping lanes and is a major fishery. The coast is a popular destination for recreation and tourism in bordering countries, and a rich source of energy resources, including wind and wave power.

The Gallic Wars were waged between 58 and 50 BC by the Roman general Julius Caesar against the peoples of Gaul (present-day France, Belgium, and Switzerland). Gallic, Germanic, and Brittonic tribes fought to defend their homelands against an aggressive Roman campaign. The Wars culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul. Though the collective Gallic armies were as strong as the Roman forces, the Gallic tribes' internal divisions eased victory for Caesar. Gallic chieftain Vercingetorix's attempt to unite the Gauls under a single banner came too late. Caesar portrayed the invasion as being a preemptive and defensive action, but historians agree that he fought the wars primarily to boost his political career and to pay off his debts. Still, Gaul was of significant military importance to the Romans. Native tribes in the region, both Gallic and Germanic, had attacked Rome several times. Conquering Gaul allowed Rome to secure the natural border of the river Rhine.

The wars began with conflict over the migration of the Helvetii in 58 BC, which drew in neighboring tribes and the Germanic Suebi. By 57 BC, Caesar had resolved to conquer all of Gaul. He led campaigns in the east, where the Nervii almost defeated him. In 56 BC, Caesar defeated the Veneti in a naval battle and took most of northwest Gaul. In 55 BC, Caesar sought to boost his public image. He undertook first-of-their-kind expeditions across the Rhine and the English Channel. Rome hailed Caesar as a hero upon his return from Britain, though he had achieved little beyond landing because his army had been too small. The next year, he returned with a larger army and reached much further inland; he extracted tribute from the locals and returned to Gaul. Tribes rose up on the continent, and the Romans suffered a humiliating defeat. 53 BC saw a brutal pacification campaign. That failed, and Vercingetorix led a revolt in 52 BC. Gallic forces won a notable victory at the Battle of Gergovia, but the Romans' indomitable siege works at the Battle of Alesia crushed the Gallic coalition.