Scamander (Skamandros), called Xanthus by the gods, is the river-god of the stream that flowed from Mount Ida across the Trojan plain to the Hellespont. Son of Oceanus and Tethys — or alternately of Zeus — he fathered Teucer by the nymph Idaea and stands in the ancestry of Troy's royal house. In the Iliad he fights for the Trojans against Achilles until Hera, Athena, and Hephaestus force him back.
Adapted from Wikipedia, "Scamander" · CC BY-SA 4.0
I.Family and geography
Hesiod numbers Scamander among the river-sons of Oceanus and Tethys; other accounts make him a son of Zeus. By the water-nymph Idaea he fathered King Teucer, first ruler of the Teucrian land. Later genealogies also name him father of Glaucia, of Eurythemista (in one tradition mother of Pelops and Niobe by Tantalus), and of Strymo or Rhoeo, wife of Laomedon; Apollodorus places his daughter Callirrhoe in the line of Tros and Ilus.
The Scamander River surrounded Troy's plain. Homer gives it two springs — one warm, one cold in every season — and sets the Achaean camp near its mouth, so that the battles of the war are fought on Scamander's plain.
II.Achilles and the river
In Iliad 20–21 the river fights for Troy after Achilles insults him. Scamander tries three times to overwhelm the hero; Achilles is saved only when Hera, Athena, and Hephaestus intervene — Hephaestus's fire drying the flood. The episode personifies the stream that rose on Ida and joined the Hellespont north of the city.
III.Later anecdote
Pseudo-Plutarch's De fluviis tells that Scamander went mad during the mysteries of Rhea and flung himself into the river Xanthus, which was thereafter renamed Scamander — an aetiology that doubles the god and the renamed stream.