he served seleucus and antiochus for several decades. after exploring the caspian sea, patrocles concluded that the caspian was a gulf or inlet that could be entered from the indian ocean. the only information on his work (even the title is unknown) is documented in the work of strabo. as a military officer, patrocles was a skilled engineer, and at one point managed to defend babylonia for seleucus against demetrius poliorcetes by flooding the irrigation canals.