Celtic Sea in the context of "St George's Channel"

The Bay of Biscay (/ˈbɪskeɪ, -ki/ BISS-kay, -⁠kee) also known as the Gulf of Biscay or the Gulf of Gascony is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and along the northern coast of Spain, extending westward to Cape Ortegal.

The average depth is 1,744 m (5,722 ft) and the greatest depth is 4,735 m (15,535 ft).

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.

Ireland (Irish: Éire [ˈeːɾʲə] ), also known as the Republic of Ireland (Poblacht na hÉireann), is a country in Northwestern Europe. It consists of 26 of the 32 counties of the island of Ireland, with a population of about 5.4 million. Its capital and largest city is Dublin, on the eastern side of the island, with a population of over 1.5 million. The sovereign state shares its only land border with Northern Ireland, which is part of the United Kingdom. It is otherwise surrounded by the Atlantic Ocean, with the Celtic Sea to the south, St George's Channel to the south-east and the Irish Sea to the east. It is a unitary, parliamentary republic. The legislature, the Oireachtas, consists of a lower house, Dáil Éireann; an upper house, Seanad Éireann; and an elected president (Uachtarán) who serves as the largely ceremonial head of state, but with some important powers and duties. The head of government is the Taoiseach (prime minister, lit. 'chief'), elected by the Dáil and appointed by the president, who appoints other government ministers.

The Irish Free State was created with Dominion status in 1922, following the Anglo-Irish Treaty. In 1937, a new constitution was adopted, in which the state was named "Ireland" and effectively became a republic, with an elected non-executive president. It was officially declared a republic in 1949, following The Republic of Ireland Act 1948. Ireland became a member of the United Nations in 1955. It joined the European Communities (EC), the predecessor of the European Union (EU), in 1973. The state had no formal relations with Northern Ireland for most of the 20th century, but the 1980s and 1990s saw the British and Irish governments working with Northern Irish parties to resolve the conflict that had become known as the Troubles. Since the signing of the Good Friday Agreement in 1998, the Irish government and Northern Irish government have co-operated on a number of policy areas under the North/South Ministerial Council created by the Agreement.

Wales (Welsh: Cymru [ˈkəmrɨ] ) is a country that is part of the United Kingdom. Located on the island of Great Britain, it is bordered by the Irish Sea to the north and west, England to the east, the Bristol Channel to the south, and the Celtic Sea to the south-west. As of 2021, it had a population of 3.2 million. It has a total area of 21,218 square kilometres (8,192 sq mi) and over 2,700 kilometres (1,680 mi) of coastline. It is largely mountainous with its higher peaks in the north and central areas, including Snowdon (Yr Wyddfa), its highest summit. The country lies within the north temperate zone and has a changeable, maritime climate. Its capital and largest city is Cardiff.

A distinct Welsh culture emerged among the Celtic Britons after the Roman withdrawal from Britain in the 5th century, and Wales was briefly united under Gruffudd ap Llywelyn in 1055. After over 200 years of war, the conquest of Wales was completed by King Edward I of England in 1283, though Owain Glyndŵr led the Welsh Revolt against English rule in the early 15th century, and briefly re-established an independent Welsh state with its own national parliament (Welsh: senedd). In the 16th century the whole of Wales was annexed by England and incorporated within the English legal system under the Laws in Wales Acts 1535 and 1542. Distinctive Welsh politics developed in the 19th century. Welsh Liberalism, exemplified in the late 19th and early 20th century by David Lloyd George, was displaced by the growth of socialism and the Labour Party. Welsh national feeling grew over the century: a nationalist party, Plaid Cymru, was formed in 1925, and the Welsh Language Society in 1962. A governing system of Welsh devolution is employed in Wales, of which the most major step was the formation of the Senedd (Welsh Parliament, formerly the National Assembly for Wales) in 1998, responsible for a range of devolved policy matters.

Ireland is an island in Northern Europe, in the north Atlantic Ocean. The island measures about 480 km (300 mi) north-south, and 275 km (171 mi) east-west, with a total area of 84,421 km (32,595 sq mi). It lies about 53°N 8°W / 53°N 8°W / 53; -8, near the western edge of the European continental shelf, part of the Eurasian Plate. Ireland is separated from the island of Great Britain by the Irish Sea to the east, and from mainland Europe by the Celtic Sea to the south. It is bounded to the north by the North Channel and to the south by St George's Channel. Ireland is the second-largest landmass in the British Isles, after Great Britain and before Lewis and Harris.

Its main geographical features include low central plains surrounded by coastal mountains. The highest peak is Carrauntoohil (Irish: Corrán Tuathail), which is 1,039 metres (3,409 ft) above sea level. The western coastline is rugged, with many islands, peninsulas, headlands and bays, while the southern and northern coasts have a smaller number of substantial sea inlets, such as Lough Foyle and Cork Harbour; no part of the land is more than around 110 km (68 mi) from the sea. The island is almost bisected by the River Shannon, which at 360.5 km (224 mi) with a 102.1 km (63 mi) estuary is the longest river in Ireland and flows south from County Cavan in the province of Ulster to form the boundary between Connacht and Leinster, and later Munster, and meet the Atlantic just south and west of Limerick. Lough Neagh is the largest of several sizeable lakes along Ireland's rivers.

Shown here are all the major rivers and tributaries of Ireland with their lengths (in kilometres and miles). Starting with the Northern Ireland rivers, and going in a clockwise direction, the rivers (and tributaries) are listed in regard to their entry into the different seas: the Irish Sea, the Celtic Sea and the Atlantic Ocean. Also shown are two tables. Table 1 shows the longest rivers in Ireland with their lengths (in kilometres and miles), the counties they flow through, and their catchment areas (in square kilometres). Table 2 shows the largest rivers in Ireland (by mean flow) in cubic metres per second.

The longest river in Ireland is the River Shannon, at 360.5 kilometres (224.0 mi). The river develops into three lakes along its course, Lough Allen, Lough Ree and Lough Derg. Of these, Lough Derg is the largest. The Shannon enters the Atlantic Ocean at the Shannon Estuary. Other major rivers include the River Liffey, River Lee, River Swilly, River Foyle, River Lagan, River Erne, River Blackwater, River Nore, River Suir, River Barrow (The Three Sisters), River Bann, River Slaney, River Boyne, River Moy and River Corrib.

Brittany (/ˈbrɪtəni/ BRIT-ən-ee) is a peninsula, historical country and cultural area in the north-west of modern France, covering the western part of what was known as Armorica in Roman Gaul. It became an independent kingdom and then a duchy before being united with the Kingdom of France in 1532 as a province governed as a separate nation under the crown. Brittany is the traditional homeland of the Breton people and is one of the six Celtic nations, retaining a distinct cultural identity that reflects its history.

Brittany has also been referred to as Little Britain (as opposed to Great Britain, with which it shares an etymology). It is bordered by the English Channel to the north, Normandy to the northeast, eastern Pays de la Loire to the southeast, the Bay of Biscay to the south, and the Celtic Sea and the Atlantic Ocean to the west. Its land area is 34,023 km (13,136 sq mi).