It originates on a planet called Coba, a former colony of the Ruby Empire that became isolated during the empire's collapses and remains so even during the time of the novels.
Ottoman Empire | Order of the British Empire | Russian Empire | Roman Empire | British Empire | Holy Roman Empire | German Empire | Byzantine Empire | Mughal Empire | Austrian Empire | First French Empire | Ruby | Empire of Japan | Empire State Building | Vijayanagara Empire | Spanish Empire | Boardwalk Empire | Empire | Mongol Empire | Second French Empire | Order of the Indian Empire | Portuguese Empire | Achaemenid Empire | Ruby (programming language) | Parthian Empire | Maratha Empire | Western Roman Empire | Seleucid Empire | The Empire Strikes Back | Hackney Empire |