In Greek mythology, Ilus (Ancient Greek Ἶλος) son of Dardanus is an early king of Dardania who dies childless; the kingship passes to his brother Erichthonius, ancestor of Tros and the later Trojans. Distinct from Ilus son of Tros (founder of Ilium), from Ilus son of Mermerus in the Odyssey, and from Virgil's Italian ally Ilus.
Adapted from Wikipedia, "Ilus (son of Dardanus)" · CC BY-SA 4.0
I.Eldest son of Dardanus
Ilus is the eldest son of Dardanus by Batea (daughter of Teucer) or, in some accounts, Olizone. His brother Erichthonius becomes the productive line; some variants name Erichthonius and Zacynthus instead of Ilus and Erichthonius.
After Dardanus dies, Ilus succeeds to the Dardanian throne. Apollodorus records that he dies without heirs, so Erichthonius gains the kingdom and begets Tros — the fork that leads to Ilus the city-founder, Assaracus, and Ganymede.
II.Tomb and Homonym care
Homer's Iliad repeatedly mentions the tomb of Ilus in the Trojan plain — usually understood as the monument of the later Ilus son of Tros, though the name-group binds the dynasty's memory to the plain.
The atlas id ilus-childless is Dardanus' heirless son alone. Do not merge with the founder of Troy (Ilus son of Tros) or with Odyssey Ilus of Ephyra.