The Hellenistic Period is a part of the Ancient Period for the European and Near Asian space. The use of this period is justified by the extent of the Hellenic culture in most of these areas, due to the Greek political presence especially in Asia after Alexander's conquests, but also to a new wave of Greek colonization. In consequence, the Hellenistic Period is usually accepted to begin in 323 BC with Alexander's death and ends in 31 BC with the conquest of the last Hellenistic kingdom by Rome, the Lagid kingdom of Egypt. For the Asian part, we could lengthen it to 10 BC, when the last Indo-Greek kingdom was conquered by Indo-Sakas.
Politically, the Hellenistic Period is characterized by a division and a split from Alexander's former empire, with endless wars between the Diadochi and their successors. Thus the Hellenistic kingdoms weakened themselves and thus gradually created space for competing kingdoms, such as Pontus or Bactria. At the same time, Roman power was in exponential expansion, annihilating other political presence in Italy, and then the Carthaginian dominance of the Mediterranean in the three Punic Wars. At the end of the Hellenistic Period the young Roman Empire had almost reached its maximum expansion, from Lusitania (modern Portugal) to Syria and from South-Britain to Egypt.