In Greek mythology, Nauplius (Ancient Greek: Ναύπλιος, "seafarer") is the name of one or more mariner heroes. Apollodorus identifies the son of Poseidon and Amymone — eponymous founder of Nauplia and a famous navigator — with the long-lived "Nauplius the Wrecker," father of Palamedes, who wrecked the Achaean returns from Troy in revenge for his son's death.
Adapted from Wikipedia, "Nauplius (mythology)" · CC BY-SA 4.0
I.Son of Poseidon and Amymone
Poseidon fathered Nauplius by Amymone, daughter of Danaus. This Nauplius was reputed founder of Nauplia in Argolis and a navigator who discovered the constellation Ursa Major. Pherecydes makes him ancestor of Dictys and Polydectes of Seriphos. Apollonius of Rhodes treats him as ancestor of a later Argonaut of the same name (Nauplius – Proetus – Lernus – Naubolus – Clytoneus – Nauplius), while Hyginus conflates the son of Poseidon with the Argonaut himself.
II.Father of Palamedes
Nauplius the Wrecker, king of Euboea and father of Palamedes, Oeax, and Nausimedon, is the figure of the Trojan-cycle revenge tales. Apollodorus says he is the same as Poseidon's son and "lived to a great age"; wives named in different sources include Philyra (Nostoi), Hesione (Cercops), and Clymene (the tragic poets). No surviving ancient source identifies the Argonaut with the father of Palamedes.
Kings entrusted unwanted daughters to him: Catreus of Crete handed over Aerope (and sometimes Clymene) to be drowned or sold — Nauplius spared Aerope and gave her to Pleisthenes, and in Apollodorus took Clymene as his own wife. Aleus of Tegea similarly gave him pregnant Auge; Nauplius sold her on to Teuthras of Mysia rather than drown her.
III.Revenge for Palamedes
After the Greeks killed Palamedes at Troy through Odysseus's treachery, Nauplius demanded justice and was refused. He then lit false beacon fires on the rocks of Cape Caphereus in Euboea during the homeward storm, luring many Achaean ships to wreck; Hyginus adds that he killed survivors who swam ashore. He was also said to have corrupted the wives of Agamemnon, Diomedes, and Idomeneus, and to have convinced Odysseus's mother Anticleia that her son was dead, whereupon she hanged herself.
Homer mentions the storm that killed Ajax the Lesser but not Nauplius; the Nostoi and later tragedy made the revenge famous. Aeschylus, Sophocles, and Euripides each wrote a Palamedes; Sophocles is credited with Nauplios Katapleon and Nauplios Pyrkaeus. Apollodorus remarks that setting false beacons was Nauplius's habit, and that he himself died in the same way.