1803, in reference to dynasty founded in Syria 312 B.C.E. by Seleucus Nicator, general of Alexander. It lasted until the Roman conquest 65 B.C.E. The Seleucidan Era, a local reckoning in the East (maintained by Syrian Christians) usually is dated to Sept. 1, 312 B.C.E.[Seleucid etymology, Seleucid origin, 英语词源]