The annihilation of 3 legions at Teutoburger Wald in 9 A.D. made this German river the limit of Roman expansion
[DOC] [TLE] worst strategic decision / mistake - Taleworlds Forum [PAR] The Romans already had Germania, or well, up until the Elbe rivers, ... My point is 
that DESPITE the defeat at Teutoburg the Romans could ... See Battle of Mainz 
and The crossing of the Rhine in AD 406 ...