Oisin

In Celtic* mythology, Oisin (or Ossian) was a great warrior poet and the son of Finn, leader of a warrior band known as the Fianna. Legend says that an enchanter had changed Finn's lover, the goddess Sadb, into a deer. One day while looking for Sadb, Finn came upon Oisin. He realized the boy was his son after Oisin told him that his mother was a gentle deer. Finn raised Oisin and trained him to be a warrior, but Oisin also inherited his mother's gift of eloquent speech. He became a great poet as well as one of the fiercest warriors of the Fianna.

As a man, Oisin met Niamh, daughter of the sea god Manannan Mac Lir. She invited him to visit her father's kingdom of Tir Na Nog, the Land of Ever Young. Oisin stayed there for 300 years, although it seemed like only a few weeks. Lonely for home, he asked if he might visit Ireland. Niamh agreed and sent him back on horseback, warning him not to touch the ground or he would never return to Tir Na Nog. However, Oisin slipped and fell to the ground, instantly becoming a blind old man who never saw his beloved Niamh again. In 1761, a writer named James Macpherson published what was claimed to be a translation of Ossian's poems. Their authenticity was disproved by Samuel Johnson 14 years later.