The Simoeis was a small river of the ancient Troad, having its source in Mount Ida, or more accurately in Mount Cotylus, which passed by Troy, joined the Scamander River below that city.
[3] The river is also noted by the ancient geographers Strabo,[4] Ptolemy,[5] Stephanus of Byzantium,[6] Pomponius Mela,[7] and Pliny the Elder.
[8] Its present course is so altered that it is no longer a tributary of the Scamander, but flows directly into the Hellespont.
Scamander, another river who also supported the Trojans, called upon Simoeis for help in his battle against Achilles:"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 man who 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.