In Greek mythology, Menestheus son of Peteos was the Athenian king who led fifty black ships to Troy. Set up while Theseus was trapped in the underworld, he excelled at marshalling chariots and shield-bearers (second only to Nestor in Homer) and after the war is said to have ruled Melos.
Adapted from Wikipedia, "Menestheus" · CC BY-SA 4.0
I.Kingship of Athens
Menestheus is son of Peteos (son of Orneus, son of Erechtheus); his mother is given as Polyxene or Mnesimache. When Theseus goes to Hades after abducting Helen, Castor and Pollux install Menestheus; he expels Theseus' sons. On Theseus' return Menestheus drives him out — Theseus flees to Lycomedes on Scyros and dies there. After Menestheus' death (a 23-year reign in Eusebius) Athens returns to Theseus' line under Demophon.
II.At Troy and afterward
As a suitor of Helen he brings fifty black ships. Homer praises his marshalling above all others save Nestor; Herodotus' Athenian embassy echoes that fame. The Iliad also shows him reluctant in the rear ranks and calling Ajax and Teucer when Sarpedon attacks his sector of the wall. He is counted among those in the Wooden Horse.
After the sack he sails toward Mimas and then to Melos, where he becomes king when Polyanax dies.