Complex sentence: Artasyras, the chief of the Hyrcanians, came, with 50.000 men, and recognized Cyrus as King; afterwards came the chiefs of the Parthians, Sacse, Bactrians, and other nations, each seeking to arrive before the other.
Split into simpler sentences: Artasyras, the chief of the Hyrcanians, came, with 50.000 men, and recognized Cyrus as King. Soon the chiefs of the Parthians, Bactrians, Sacse and other nations, each seeking to arrive before the other.