In many scenarios a mighty empire dooms itself through its hubris: it presumes to conquer and rule an entire galaxy. That seems a lofty ambition indeed. To bring the Milky Way galaxy to heel, an empire would have to vanquish 100 billion stars. But cosmologists—those astronomers who study the universe as a whole— are unimpressed. The Milky Way is one of 50 billion or more galaxies within the observable reaches of space. To conquer it would be to conquer an insignificant speck.