Roma I was an alternate Earth where the Roman Empire never fell and lasted into the 20th century.
After Marcus Americanius Scriptor obtained a time ring that allowed him to travel to other parallel Earths, he named his Earth Roma I for convenience. When it was discovered that it was also the most advanced of the Earths where Rome ruled, it became the most influential member of the Empire of Empires. (PROSE: Warlords of Utopia)