He entered Trinity College Dublin, on 4 July 1803, but left without a degree, and due to poor health he was forced to abandon the pursuit of the legal profession and admission to the Irish Bar.
[2] Keightley is known to have contributed tales to Thomas Crofton Croker's Fairy Legends of South Ireland (1825), though not properly acknowledged.
Having spent time in Italy,[4] he was capable of producing translations of tales from Pentamerone or The Nights of Straparola in Fairy Mythology, and he struck up a friendship with the patriarch of the Rossetti household.
Thomas claimed to be literate in twenty-odd languages and dialects in all,[5] and published a number of translations and digests of medieval and foreign works and passages, often sparsely treated elsewhere in the English language, including the expanded prose versions of Ogier the Dane which conveys the hero to Morgan le Fay's Fairyland, or Swedish ballads on nixes and elves, such as Harpans kraft ("Power of the Harp") and Herr Olof och älvorna [sv] ("Sir Olof in Elve-Dance").
[2] It was popular among Victorian folklore researchers and literary figures in its day; an expanded edition appeared in 1850, and a newly prefaced one in 1860.
It has subsequently been reissued intermittently up to modern times,[10] vindicating Keightley's own "high hopes of immortality for his work" in his preface, despite an early biographer calling this "pretentious".
[15] A selection in Fairy Mythology was an Irish mermaid story entitled "The Soul Cages," which turned out to be a hoax of sorts.
[b][18] The 1878 edition was reprinted a century later retitled as The World Guide to Gnomes, Fairies, Elves and Other Little People (New York: Avenel Books, 1978).
[19][20] Keightley's bowdlerized The Mythology of Ancient Greece and Italy for the Use of School (1831) was applauded by Thirlwall for making the subject "fit for ladies."
But he ludicrously overestimated all his performances, and his claim to have written the best history of Rome in any language, or to be the first to justly value Virgil and Sallust, could not be admitted by his friends.
[31] He is listed among the "distinguished file" in one survey of past commentaries on Milton, going back three centuries (Miner, Moeck & Jablonski (2004)).
Though that may be so according to the genealogy laid out by Hesiod's Theogony, it has been pointed out that Milton could well have used alternate sources, such as Lactantius's Divinae Institutiones ("Divine Institutes"), which quotes Ennius to the effect that Uranus had two sons, Titan and Saturn.
[2] Keightley is credited with first noticing that Chaucer's Squire's Tale is paralleled by, and hence may have drawn from, the Old French romance, Adenes Le Roi's Cléomadès.
[36][37] He also wrote of Henry Fielding's peculiarism of using the antiquated "hath" and "doth" ( Fraser's Magazine, 1858), without acknowledging a commentator who made the same observation before him.
William Michael Rossetti's Memoir notes that Keightley had as "his nephew and adopted son, Mr. Alfred Chaworth Lyster" who became a dear friend.