Original sentence: Following the Hellenistic period (300 - 250 BCE) came the Parthian (250 BCE - 226 CE ) and the Sassanid (226 - 651) dynasties.The first true empire of global proportions of Persia blossomed under the Achaemenids in (559 - 330 BCE).The sixth millennium BCE saw a fairly sophisticated agricultural society and proto-urban population centers
Edited sentence: Following the Hellenistic period (300 - 250 BC) came the Parthian (250 BC - AD 226 ) and the Sassanid (226 - 651) dynasties.The first true empire of global proportions of Persia blossomed under the Achaemenids in (559 - 330 BC).The sixth millennium BC saw a fairly sophisticated agricultural society and proto-urban population centers