An empire is a large group of territories or nations that are ruled by a single authority, often an emperor or empress. Empires can span vast areas and include diverse cultures, languages, and peoples. They are usually formed through conquest, colonization, or political alliances, and they often seek to expand their influence and control over other regions. Throughout history, many famous empires have existed, such as the Roman Empire, the British Empire, and the Ottoman Empire. These empires have left lasting impacts on the world, shaping trade, culture, and politics. The rise and fall of empires often reflect the changing dynamics of power and society.