The transition from the Classical to the Hellenistic period occurred during the 4th century BC. Greek art became increasingly diverse, influenced by the cultures of the peoples drawn into the Greek orbit, by the conquests of Alexander the Great (336 to 323 BC). In the view of some art historians, this is described as a decline in quality and originality; however, individuals of the time may not have shared this outlook. Many sculptures previously considered classical masterpieces are now known to be of the Hellenistic age. The technical ability of the Hellenistic sculptors are clearly in evidence in such major works as the "Winged Victory of Samothrace", and the Pergamon Altar. New centres of Greek culture, particularly in sculpture, developed in Alexandria, Antioch, Pergamum, and other cities. By the 2nd century BC, the rising power of Rome had also absorbed much of the Greek tradition—and an increasing proportion of its products as well.