In 1707, Scotland and England were joined in the Act of Union to make one big Kingdom, the Kingdom of Great Britain. When Ireland joined in 1801, the United Kingdom was created. Scotland was an important part of the colonialism and imperialism of the British Empire. Scots colonists emigrated throughout the empire, and a large diaspora of Scots lives throughout the world as a result. The Scottish Enlightenment was an important part of the Age of Enlightenment. Philosophers like David Hume and Adam Smith led the Scottish Enlightenment.