England is a territory in the United Kingdom, as well as Wales to the west and Scotland to the north sharing the same island of Great Britain, as well as Northern Ireland, a small portion of north Ireland, as the rest of the island is known as the Republic of Ireland. It was first inhabited by Celtic people, but when the Romans conquer the island as Britannia in 43 AD, they moved to Scotland and Cornwall in the main island, Ireland, Isle of Man and Brittany in France. Later in the 5th century AD, Germanic tribes from northern Germany and Denmark known as the Anglo-Saxons, most notably the Angles that gave name to the modern territory, invaded the island. They established some kingdoms like Mercia, Wessex and Sussex (Mercia- UDI 1995 is an alternate history on this wiki with the POD in that time). There were many disputes and struggles on those kingdoms and Danish invaders would overthrow them. The only surviving kingdom was Wessex under Alfred the Great, in which expanded and unified England by his successors. The nation would later be controlled by Normans, Scandinavians that settled in Northern France, lead by Duke William of Normandy in 1066 over a dispute of the succession of Edward the Confessor. It later became part of the Angevin Empire, ruling from Pyrenees in the Spanish-French border to Ireland around the 12th and 13th centuries, in which eventually collapsed and England became independent in the 1210s. During the renaissance period, Anglicanism, a form of Protestantism, was established under King Henry VIII because the Catholic Church denied the divorce of the king's wife. His daughters, Elizabeth I and Mary I, brought Catholicism back.
England had competed with other European colonial powers such as Spain and France in the West Indies and the Pacific starting in the 16th century. Meanwhile in the island, King James VI, in which inherited the throne as James I, unifying England with Scotland forming the Union of Crowns in 1603. Later, the English Civil War began between disputed of the Parliament and the Puritans from the south, versus King Charles I and the Royalists from the north, and involved both Scotland and Ireland, which is why it was also known as the War of the Three Kingdoms. The Puritans won and King Charles I was executed, to be later ruled by Oliver Cromwell in and the monarchy was restored by King Charles II in 1660. Under the newly formed Kingdom of Great Britain, output from the Royal Society and other English initiatives combined with the Scottish Enlightenment to create innovations in science and engineering, while the enormous growth in British overseas trade protected by the Royal Navy paved the way for the establishment of the British Empire. This drove the country to the Industrial Revolution where people started to work on factories in urbanised cities. During the Napoleonic Wars, the country was under threat of invasion by France, along with the help of Spain and the Batavian Republic, but was called off.
London became the largest city in the country. Power shifts in east-central Europe led to World War I; hundreds of thousands of English soldiers died fighting for the United Kingdom as part of the Allies. Two decades later, in World War II, the United Kingdom was again one of the Allies. At the end of the Phoney War, Winston Churchill became the wartime Prime Minister. Developments in warfare technology saw many cities damaged by air-raids during the Blitz. Following the war, the British Empire experienced rapid decolonisation, and there was a speeding up of technological innovations; automobiles became the primary means of transport and Frank Whittle's development of the jet engine led to wider air travel. England soon faced decolonisation of most of its territories in the West Indies and the Pacific, and there was also a technological innovations of vehicles and engineering.
Since the 20th century there has been significant population movement to England, mostly from other parts of the British Isles, but also from the Commonwealth, particularly the Indian subcontinent. Since the 1970s there has been a large move away from manufacturing and an increasing emphasis on the service industry. As part of the United Kingdom, the area joined a common market initiative called the European Economic Community which became the European Union. Since the late 20th century the administration of the United Kingdom has moved towards devolved governance in Scotland, Wales and Northern Ireland. England and Wales continues to exist as a jurisdiction within the United Kingdom. Devolution has stimulated a greater emphasis on a more English-specific identity and patriotism. There is no devolved English government, but an attempt to create a similar system on a sub-regional basis was rejected by referendum.