What happen in the Hellenistic era?

During this time, Greek cultural influence and power was at its zenith in Europe and Asia. It is often considered a period of transition, sometimes even of decline or decadence between the brilliance of the Greek Classical Era and the emergence of the Roman Empire. Usually taken to begin with the death of Alexander in 323 BC, the Hellenistic period may either be seen to end with the final conquest of the Greek heartlands by Rome in 146 BC; or the final defeat of the last remaining successor-state to Alexander's empire, the Ptolemaic kingdomof Egypt in 31/30 BC . The Hellenistic period was characterized by a new wave of Greek colonization which established Greek cities and kingdoms in Asia and Africa.