A Scottish schoolmaster, James MacPherson (1736-1796), achieved some literary fame in the late 18thC. when he claimed to have translated a series of poems written by a 3rdC. Irish (then, Scottish) poet named Ossian (or Oisin in Gaelic). On the basis of his translations, MacPherson became a celebrated author, a diplomat, and a member of Parliament. Even though initial reaction to the Ossian translations excited the literary world in Great Britain, which was thrilled to have a British version of the Homeric Epic, many literary scholars--Samuel Johnson among them--were critical of the poems' literary quality and suspected their authenticity. In the mid-to-late 18thC., however, all things medieval and Celtic were beginning to interest writers and historians, and the Ossian translations arrived on the literary scene at the perfect time in 1773.
Ossian's poetry appears to have been based on the Homeric Epic (in fact, Ossian was supposed to have been blind, like Homer), whose main character Fingal engages in epic struggles with the Irish, Vikings, and even the Romans. Ossian's poetry, even though its subject is indeed epic struggle, is often extremely dull while expressing lofty sentiments:
O! thou who travellest above, round as the full-orbed hard shield of the mighty! whence is thy brightness without frown, thy light that is lasting, O sun? Thou comest forth in thy powerful beauty, and the stars bide their course; the moon, without strength, goes from the sky, hiding herself under a wave in the west.
This, unfortunately, is a typical sample of Ossian's poetry, which uses heavily latinate diction and completely conventional imagery to convey in fifty words what a skillful poet might in ten.
Many literary critics and learned men of the day--Johnson, Gibbon, Thomas Gray--began to suspect Ossian's authenticity, particularly when MacPherson, when challenged, could not come up with the original poetry from which he made his translations.
On the Continent and in Britain, however, many writers and readers--Goethe, Napoleon, Hazlitt included--were enthusiastic supporters of MacPherson's "translations," and in Sorrows of Young Werther (1774), Goethe's main character, Werther, enthusiastically says that "Ossian has dispossessed Homer in my heart." For many of the Romantics, Thomas Hazlitt, for example, MacPherson's Ossian expressed the tenets of the Romantics' view of the world and poetry. The fact that the Ossian translations were undoubtedly fake is beside the point.