Ossian (; Irish Gaelic/Scottish Gaelic: Oisean) is the narrator and purported author of a cycle of epic poems published by the Scottish poet James Macpherson, originally as Fingal (1761) and Temora (1763), and later combined under the title The Poems of Ossian. Macpherson claimed to have collected word-of-mouth material in Scottish Gaelic, said to be from ancient sources, and that the work was his translation of that material. Ossian is based on Oisín, son of Fionn mac Cumhaill (anglicised to Finn McCool), a legendary bard in Irish mythology.
https://en.wikipedia.org/wiki/Ossian