At 6 a.m. On June 20, 1837, Queen Victoria was roused from sleep at Kensington Palace and told that her uncle, King William IV, had died, making her, at 18, the sovereign of the United Kingdom. She met the Lord Chamberlain and the Archbishop of Canterbury alone, without her domineering mother in the room, and in that first act of solitary authority announced exactly what kind of reign it would be. Over the next 64 years, Victoria presided over the British Empire at the height of its power, stretching across roughly a quarter of the globe and reshaping economies, borders, and cultures from India to Africa to the Caribbean. She outlasted dozens of prime ministers, survived eight assassination attempts, and gave her name to an entire era of industrialization, reform, and imperial expansion. The Victorian era codified legal systems, railways, and governance structures that dozens of nations still carry in their bones today.