Simplify the following text for a Grade 10 native English-speaking person.
Original: Crassus was killed by Parthian forces after treacherous guides led him astray during the retreat from Carrhae , but Cassius managed to escape with 500 cavalry and meet up with the surviving legionaries .
Simplified: Crassus was killed , but Cassius managed to escape with 500 cavalry and meet up with the surviving legionaries .