Assrachus, in Greek mythology, tried to reign in Troy while his older brother, Ilo II was away (in another version, he is Ilo II's nephew). When he returned, Ilo dispatched the usurper. So Assarachus had to be content with reigning only in Dardania.
In the text attributed to Dictis of Crete, Assrachus is the son of Cleomestra, and was related to Priam and the Greeks who attacked Troy during the Trojan War. Tros, son of Erictonius of Dardania, son of Dardanus, was the father of Ilo II, Ganymede and Cleomestra, and Cleomestra was the mother of Assrachus.
By this lineage, Dardanus is the son of Electra and Zeus, but Electra is not the daughter of the titanid Pleione,but the daughter of Hesione, one of the Danaids. Priam was his relative, because he was the son of Laomedon, the son of Ilo II.
Antenor was the brother (or half-brother) of Assrachus, for he was the son of Cleomestra and Esietes.
Assarachus married Hieromneme, sister of Astiochus, and with her he had as his son Capis. Their son Capis was the father of Anquises.
He is the grandfather of Anquises, father of Aeneas, who after the fall of Troy headed to Latium in Italy to found a new city. He is mentioned in Virgil's Aeneid (1,284-285).
According to the Latin poet, the Romans are his descendants, and since Rome was the new Troy, the "sons of Assrachus" conquered the country from the Greeks in 146 BCE. The conquest of Greece by Rome is presented by Virgil as a distant revenge of fate after the fall of Troy.