In the story of "Breuddwyd Macsen Wledig" (English: "The Dream of Emperor Maximus"), he is Emperor of Rome and marries a wondrous British woman, telling her that she may name her desires, to be received as a wedding portion. She asks that her father be given sovereignty over Britain, thus formalising the transfer of authority from Rome back to the Britons themselves. The marriage also makes possible British descendants, a point not lost on medieval kings. The earliest Welsh genealogies give Maximus the role of founding father for several royal dynasties, including those of Powys and Gwent, a role he also played for the rulers of medieval Galloway in Scotland, home to the Roman-era Novantae whose territory was also made independent of Roman rule by Maximus. He is given as the ancestor of a Welsh king on the Pillar of Eliseg, erected nearly 500 years after he left Britain, and he figures in lists of the Fifteen Tribes of Wales.