Charles I (Charlemagne) was crowned emperor in 800 by the pope, inheriting the Roman Empire through a line from Augustus and Constantine. His empire was vast and sprawling, rather than a single unit, with no fixed capital. Like other great empires of the time, Charlemagne claimed universality and cosmopolitanism. In the early 15th century, Portuguese voyages down the west coast of Africa, sponsored by Prince Henry, began changing visions of the world and eventually led to direct trade routes to Asia and the slave trade. The Spanish Empire of Charles V was not only a successor to Rome but also a holy empire, with Christianity accompanying European colonial expansion for centuries.