Telemachus is a figure in Greek mythology, the son of Odysseus and Penelope. A central character in the first four books of Homer's Odyssey — sometimes called the Telemachy — he grows from a passive youth overshadowed by his mother's suitors into a prince who voyages to Pylos and Sparta seeking news of his father and who stands beside Odysseus in the slaughter of the wooers.
Adapted from Wikipedia, "Telemachus" · CC BY-SA 4.0
I.In the Odyssey
When the Odyssey opens, Telemachus is a young man of about twenty who has never known his father, who left for Troy when the boy was an infant. Athena, disguised as Mentes, urges him to call an assembly, rebuke the suitors, and sail to Pylos and Sparta for news.
At Pylos, Nestor can tell him little but sends him to Menelaus in Sparta with Nestor's son Peisistratus. Menelaus reports that he heard in Egypt that Odysseus is alive but detained by the nymph Calypso. Meanwhile the suitors plot to murder Telemachus on his homeward voyage.
When Odysseus returns in disguise, father and son recognize each other in Eumaeus' hut and plan the destruction of the suitors. Telemachus helps lock the hall, stands guard during the bow-contest, and fights at his father's side.
II.Before Troy
Apollodorus tells how Palamedes exposed Odysseus' feigned madness by snatching the infant Telemachus from Penelope's arms as if to kill him, forcing Odysseus to abandon the pretence and sail to the war.