
Simoeis orSimois[1]/ˈsɪmoʊɪs/ (Ancient Greek:ΣιμόειςSimóeis) was a river of theTrojan plain, now called theDümruk Su (Dümrek Çayı),[2] and the name of its god inGreek mythology.
The Simoeis was a small river of theancient Troad, having its source inMount Ida, or more accurately inMount Cotylus, which passed byTroy, joined theScamander River below that city. This river is frequently spoken of in theIliad, and described as a rapid mountain torrent.[3] The river is also noted by the ancient geographersStrabo,[4]Ptolemy,[5]Stephanus of Byzantium,[6]Pomponius Mela,[7] andPliny the Elder.[8] Its present course is so altered that it is no longer a tributary of the Scamander, but flows directly into theHellespont.
Like other river-gods, Simoeis was the son ofOceanus andTethys.[9] Simoeis had two daughters who were married into the Trojan royal family. One daughter,Astyoche, was married toErichthonius, and the other daughter,Hieromneme was the wife ofAssaracus.
When the gods took sides in theTrojan War, Simoeis supported the Trojans.Scamander, another river who also supported the Trojans, called upon Simoeis for help in his battle againstAchilles:
"Come to my aid with all speed, fill your streams with water from your springs, stir up all your torrents, stand high in a great wave, and rouse a mighty roar of timbers and rocks, so we can stop this savage manwho in his strength is raging like the gods." (Iliad, 21.311-15).
Before Simoeis could respond,Hephaestus was able to save Achilles by subduing Scamander with flame.
 This article incorporates text from a publication now in thepublic domain: Smith, William, ed. (1854–1857). "Simois".Dictionary of Greek and Roman Geography. London: John Murray.
 This article incorporates text from a publication now in thepublic domain: Smith, William, ed. (1854–1857). "Simois".Dictionary of Greek and Roman Geography. London: John Murray.