The war ended in 71 BC when the armies of Spartacus , after long and bitter fighting , retreating before the legions of Crassus , and realizing that the legions of Gnaeus Pompeius Magnus and Marcus Terentius Varro Lucullus were moving in to entrap them , launched their full strength against Crassus ' legions and were utterly destroyed .
Realizing that the legions of Gnaeus Pompeius Magnus and Marcus Terentius Varro Lucullus were moving in to trap them , they launched their full strength against Crassus ' legions and were utterly destroyed .