In Arcadian traditions, the region was once called Pelasgia after Pelasgus, its early ruler. Some accounts describe him as earth-born; others make him a son of Zeus and Niobe. These are explanations of ancestral identity rather than securely dated accounts of a historical king. Pausanias presents Pelasgus as a civilising figure who taught people how to shelter, clothe and feed themselves, giving a mythical beginning to the customs of the land. His son Lycaon appears in the next generation. Apollodorus names Lycaon's mother as Meliboea or, in another tradition, Cyllene. The differing genealogies show that Arcadia did not preserve a single fixed family tree: its oldest rulers were remembered through stories that explained both the country and the communities within it.

Lycaon's story joins foundation traditions with a terrible violation of hospitality and sacrifice. Many of his numerous sons were linked with the names of settlements, but the family's defining act was the offering of human flesh to Zeus. The details differ sharply between sources. In Apollodorus, Lycaon's sons mix the flesh of a local child into the meal; Zeus destroys Lycaon and the sons with thunderbolts, except for Nyctimus, whom Gaia's intervention saves. Ovid instead gives a famous account in which Lycaon tries to test his guest and is transformed into a wolf. Another tradition makes the child Arcas the victim and restores him to life. Each version gives a different shape to the relationship between sacrilege, death and restoration. Together they explore the destructive consequences of crossing a sacred boundary.

Callisto and Arcas connect the Arcadian landscape with the sky. Callisto belongs to the company of Artemis, and in Ovid's account Zeus approaches her in the goddess's form and assaults her. After Arcas is born, Hera transforms Callisto into a bear. Years later, the young hunter encounters his mother without recognising her, and divine intervention prevents him from killing her. Callisto becomes the Great Bear. The identification of Arcas varies: Hyginus associates him with the Bear-Watcher, the constellation commonly known as Boötes, rather than treating the individual star Arcturus as a separate constellation. Ovid also links Hera's hostility with the bears' exclusion from the ocean. These are poetic explanations of the heavens, not an account of one unchanging star map, and they stand alongside rather than before every tradition of Arcas's kingship.

In the royal succession described by Pausanias, Arcas follows Nyctimus and gives the land its name. This royal account is distinct from the constellation stories: the sources preserve different ways of remembering the same legendary ancestor. Arcas learns agriculture from Triptolemus and teaches his people new skills, including bread-making and weaving. His wife Erato is a Dryad, a nymph of trees, not a sea nymph. Their sons Azan, Apheidas and Elatus receive portions of the country, explaining later divisions within Arcadia. Such accounts make a ruler's family into a map. They also present civilisation as something learned and passed on, with farming, clothing and settled life becoming the gifts by which the king is remembered.

The region also provides a birthplace and setting for gods with very different characters. The Homeric Hymn to Hermes places his birth to Maia on Mount Cyllene. Its compressed chronology makes him astonishingly active: born at dawn, he plays the lyre at midday and steals Apollo's cattle in the evening. His invention and theft belong to the same quick intelligence. Pan's hymn makes him the son of Hermes and an unnamed daughter of Dryops. Goat-footed and horned, he moves through mountains and wooded country, joining the life of shepherds with a divine presence that is never entirely domesticated. Other genealogies exist, but his strong Arcadian associations do not mean that he was worshipped nowhere else. Hermes and Pan give the region two related but distinct forms of supernatural energy: the ingenious traveller and the god of the wild.

The historical communities of Arcadia included Tegea, Mantinea and Megalopolis, each with its own civic and sacred landscape. Pausanias records local places and traditions rather than describing a country inhabited only by shepherds. Atalanta's Arcadian connections add hunting and heroic competition to its mythology, while other traditions carried Arcadian ancestry beyond the Peloponnese. Poetry gave the name another kind of life. In Virgil's tenth Eclogue, Pan and the Arcadian landscape surround the suffering lover Gallus; pastoral country can contain grief and frustrated desire as well as music and beauty. The later ideal of Arcadia as a refuge from complicated society grows from such literary uses, but it should not replace the region's actual history. Its enduring appeal comes from the tension between a real country and an imagined simpler life.