Answer
Caesar's death led Cassius to amass an army in the East. Cassius was a Roman senator who had been a close friend of Caesar's, but he had become disillusioned with Caesar's increasing power and ambition. After Caesar was assassinated, Cassius helped to lead the conspirators who had killed him. He then fled to the East, where he began to raise an army to oppose Caesar's adopted son and heir, Octavian.