Simplify the following text for a Grade 9 native English-speaking person.
Original: The victory over the legions was followed by a clean sweep of all Roman forts , garrisons and cities â '' of which there were at least two â '' east of the Rhine ; the remaining two Roman legions , commanded by Varus ' nephew Lucius Nonius Asprenas , were content to try to hold that river .
Simplified: The victory over the legions was followed by a clean sweep of all Roman forts , garrisons and cities â `` of which there were at least two â `` east of the Rhine . The remaining two Roman legions in Germany were stationed in a fort at Mainz , and commanded by Varus ' nephew .