Hastings' Dictionary of the Bible (1898)
PAR'THIANS, inhabitants of Parthia, were at Jerusalem during the Pentecost. Acts 2:9. They spoke the Persian language, so that, in Scripture and other ancient writing, "Persia" and "Parthia" are often used interchangeably. Coming from the ruins of the Persian empire, they were a powerful enemy to the Romans, whom they defeated at Carrhae (Haran). Under Mithridates I. their cavalry and bowmen were very expert, and dangerous to an opposing army.
They were accustomed to shoot their arrows while at full speed. They possessed, also, considerable knowledge of architecture and art. But it is for their remarkable skill in archery that they are now remembered, and for a long time they were Rome's formidable rival in the East.