Simplify the following text for a Grade 9 native English-speaking person.
Original: If the existence of the Ancient Roman Empire ( including the Western Roman Empire ) and that of the Eastern Roman\/Byzantine Empire is combined , the whole Roman Empire had existed for 1480 years .
Simplified: Many years later , after the city of Rome was taken over by Germanic people , the ` Roman ' Empire was moved to Constantinople , and a new empire was born . The new empire had a smaller territory than the original Roman Empire .