Oisín, Osian, Ossian, or anglicized as Osheen was regarded in legend as the greatest poet of Ireland, a warrior of the Fianna in the Ossianic or Fenian Cycle of Irish mythology. He is the demigod son of Fionn mac Cumhaill and of Sadhbh, and is the narrator of much of the cycle and composition of the poems are attributed to him.
Ossian playing his harp, by François Pascal Simon Gérard, 1801
Oisín and Niamh on their way to Tír na nÓg, illustration by Albert Herter, 1899
The Dream of Ossian, Jean Auguste Dominique Ingres, 1813
Irish mythology is the body of myths indigenous to the island of Ireland. It was originally passed down orally in the prehistoric era. In the early medieval era, some myths were transcribed by Christian monks, who heavily altered and Christianised the myths. Irish mythology is the best-preserved branch of Celtic mythology.
Riders of the Sidhe, a 1911 painting of the aos sí or Otherworldly people of the mounds, by the artist John Duncan
Cuchulain in Battle by Joseph Christian Leyendecker, 1911
The Fomorians, as depicted by John Duncan (1912)
Folio 53 of the Book of Leinster. Medieval manuscripts are the main source for Irish mythology and early literature.