United Kingdom of Great Britain and Ireland

The United Kingdom of Great Britain and Ireland was the unitary sovereign state created by the Acts of Union of 1801, which fused the kingdoms of Great Britain and Ireland into one. It held that form until 1922, when the Irish Free State gained independence and the remainder continued as the United Kingdom of Great Britain and Northern Ireland. Industrialisation that had begun before its formation ran on to the mid-nineteenth century, and the century was an era of the Industrial Revolution and of trade and finance in which Britain largely dominated the world economy. Heavy outward migration went to its overseas possessions and to the United States. From its islands the kingdom financed the coalitions that beat France in the Napoleonic Wars, and the Royal Navy that it built made the British Empire the foremost power for the next century. The one great exception to that prosperity was Ireland, where the failure of the potato crop in the 1840s killed more than a million people while the government did little.