Analysis of information sources in references of the Wikipedia article "Império Carolíngio" in Portuguese language version.
The size of the Carolingian empire can be roughly estimated at 1,112,000 km²
After a decade of chaos, during which the Northmen raided the Rhine cities, Arnulf, illegitimate offspring of Louis’ son Carloman, was elected king of “East Francia” (887), and drove back the invaders.