Oisin (or in Irish, Oisín), sometimes known as Ossian, was a son of Fionn mac Cumhaill and Sadb (who was the daughter of the god Bodb Dearg). He was a warrior in the Fianna and is said to have been Ireland’s greatest poet.
At or around Oisín’s birth, his mother, Sadb, had been transformed into a deer. She raised the boy while in her deer form, and for years Fionn searched for them. When he found them, he named the boy Oisín, meaning fawn.
As an adult, he was one of the Fianna’s strongest champions. One day, while he was hunting with his Fianna warriors, there came the sound of horse’s hooves. When the enchanted horse came into view, it carried on its back a beautiful young woman. She was Niamh of the Golden Hair, a daughter of the god, Manannán mac Lir.
Oisín and Niamh
Oisín fell instantly in love with her, and she begged him to journey with her to Tír Tairnigiri (the Land of Promise), where her god-family resided. In an instant, Oisín mounted her horse and they disappeared across the sea.
As the years passed, Niamh bore Oisín three children – sons, Oscar and Fionn, and a daughter, Plur na mBan, which means Flower of Women.
But Oisín longed to return to his native Ireland. Seeing his grief, Niamh offered him her enchanted horse so that he could visit Ireland, but she made him promise not to dismount and touch the soil of Ireland because three hundred years had passed and if he did so, his beautiful youth would fade from him.
Oisín hurried to Ireland and sought out the Fianna for whom he missed, but he discovered they no longer existed. Christianity now presided over Ireland. Oisín was despondent.
When he accidentally fell from the magical horse, it disappeared and Oisín changed into a decrepit old man with grey hair and cataracts in his eyes.
He died soon after, though it is said that he lived long enough to meet St Patrick and be welcomed into the new church.