What territory did the empire of Charlemagne occupy?

We are talking about the beginning of the 9th century, since Charlemagne died in 814. By this time, the borders of his empire covered the territory of modern France, Monaco, Andorra, northern Spain (up to Barcelona), Belgium, Holland, Luxembourg, Switzerland, Italy north of Rome, Austria, partly Slovenia and modern Germany, except for the territory of the former GDR, on the territory of which lived Slavic tribes – Sorbs, approved, velet. They paid tribute to the empire, but were not part of it.