The Expulsion of the Acadians, also known as the Great Upheaval, the Great Expulsion, the Great Deportation, and the Deportation of the Acadians (French: Le Grand Drangement or Dportation des Acadiens), was the forced removal by the British of the Acadian people from the present-day Canadian Maritime provinces of Nova Scotia, New Brunswick, and Prince Edward Island, and the present-day U.S. state of Maine parts of an area historically known as Acadia, causing the deaths of thousands of people. The Expulsion (17551764) occurred during the French and Indian Wars (the North American theatre of the Seven Years' War) and was part of the British military campaign against New France.

The British first deported Acadians to the Thirteen Colonies, and after 1758, transported additional Acadians to Britain and France. In all, of the 14,100 Acadians in the region, approximately 11,500 were deported, of whom at least 5,000 died of disease, starvation or in shipwrecks. Men, women and children were forcibly removed from their homes and their land, which they had farmed for a century. Their houses were burned and their land given to settlers loyal to Britain, mostly immigrants from New England and then Scotland. The event is largely regarded as a crime against humanity, though contemporary use of the term "genocide" is debated by scholars. A census of 1764 indicates that 2,600 Acadians remained in the colony having eluded capture.In 1710, during the War of the Spanish Succession, the British captured Port Royal, the capital of Acadia, in a siege. The 1713 Treaty of Utrecht, which concluded the larger conflict, ceded the colony to Great Britain while allowing the Acadians to keep their lands. However, the Acadians were reluctant to sign an unconditional oath of allegiance to Britain. Over the following decades, some participated in French military operations against the British and maintained supply lines to the French fortresses of Louisbourg and Fort Beausjour. As a result, the British sought to eliminate any future military threat posed by the Acadians and to permanently cut the supply lines they provided to Louisbourg by removing them from the area.Without making any distinction between the Acadians who had been neutral and those who had resisted the occupation of Acadia, the British governor Charles Lawrence and the Nova Scotia Council ordered them to be expelled. In the first wave of the expulsion, Acadians were deported to other British North American colonies. During the second wave, they were deported to Britain and France, and from there a significant number migrated to Spanish Louisiana, where "Acadians" eventually became "Cajuns". Acadians fled initially to Francophone colonies such as Canada, the uncolonized northern part of Acadia, le Saint-Jean (now Prince Edward Island), and le Royale (now Cape Breton Island). During the second wave of the expulsion, these Acadians were either imprisoned or deported.

Along with the British achieving their military goals of destroying the fortress of Louisbourg and weakening the Mikmaq and Acadian militias, the result of the Expulsion was the devastation of both a primarily civilian population and the economy of the region. Thousands of Acadians died in the expulsions, mainly from diseases and drowning when ships were lost. On July 11, 1764, the British government passed an order-in-council to permit Acadians to return to British territories in small isolated groups, provided that they take an unqualified oath of allegiance. Today the Acadians live primarily in eastern New Brunswick and in some regions of Prince Edward Island, Nova Scotia, Quebec and Northern Maine. American poet Henry Wadsworth Longfellow memorialized the expulsion in the popular 1847 poem, Evangeline, about the plight of a fictional character, which spread awareness of the expulsion.

The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts established by England between the late 16th and early 18th centuries.

At its height it was the largest empire in history and, for over a century, was the foremost global power. By 1913 the British Empire held sway over 412 million people, 23 per cent of the world population at the time, and by 1920 it covered 35,500,000 km2 (13,700,000 sq mi), 24 per cent of the Earth's total land area. As a result, its constitutional, legal, linguistic, and cultural legacy is widespread. At the peak of its power, it was described as "the empire on which the sun never sets", as the sun was always shining on at least one of its territories.During the Age of Discovery in the 15th and 16th centuries, Portugal and Spain pioneered European exploration of the globe, and in the process established large overseas empires. Envious of the great wealth these empires generated, England, France, and the Netherlands began to establish colonies and trade networks of their own in the Americas and Asia. A series of wars in the 17th and 18th centuries with the Netherlands and France left England (Britain, following the 1707 Act of Union with Scotland) the dominant colonial power in North America. Britain became the dominant power in the Indian subcontinent after the East India Company's conquest of Mughal Bengal at the Battle of Plassey in 1757.

The American War of Independence resulted in Britain losing some of its oldest and most populous colonies in North America by 1783. British attention then turned towards Asia, Africa, and the Pacific. After the defeat of France in the Napoleonic Wars (1803–1815), Britain emerged as the principal naval and imperial power of the 19th century and expanded its imperial holdings. The period of relative peace (1815–1914) during which the British Empire became the global hegemon was later described as "Pax Britannica" ("British Peace"). Alongside the formal control that Britain exerted over its colonies, its dominance of much of world trade meant that it effectively controlled the economies of many regions, such as Asia and Latin America. Increasing degrees of autonomy were granted to its white settler colonies, some of which were reclassified as dominions.

By the start of the 20th century, Germany and the United States had begun to challenge Britain's economic lead. Military and economic tensions between Britain and Germany were major causes of the First World War, during which Britain relied heavily on its empire. The conflict placed enormous strain on its military, financial, and manpower resources. Although the empire achieved its largest territorial extent immediately after World War I, Britain was no longer the world's preeminent industrial or military power. In the Second World War, Britain's colonies in East Asia and Southeast Asia were occupied by the Empire of Japan. Despite the final victory of Britain and its allies, the damage to British prestige helped accelerate the decline of the empire. India, Britain's most valuable and populous possession, achieved independence as part of a larger decolonisation movement, in which Britain granted independence to most territories of the empire. The Suez Crisis of 1956 confirmed Britain's decline as a global power, and the transfer of Hong Kong to China on 1 July 1997 marked for many the end of the British Empire. Fourteen overseas territories remain under British sovereignty. After independence, many former British colonies joined the Commonwealth of Nations, a free association of independent states. Fifteen of these, including the United Kingdom, retain a common monarch, currently Queen Elizabeth II.