The magician felt himself growing giddy with jealousy, not only of the touch but of something like a secret that was moving between Molly and the unicorn. "Unicorns are for beginnings," he said, "for innocence and purity. Unicorns are for young girls."
Molly was stroking the unicorn's throat as timidly as though she were blind. She dried her grimy tears on the white mane. "You don't know much about unicorns."
-- The Last Unicorn,
by Peter S. Beagle.
The classic fantasy novel The Last Unicorn (first published in 1968) presents extreme difficulties to any attempt to assign a date to its events. The only certain chronological reference given in the text can be found in its dedicatory preface: "To the memory of Dr. Olfert Dapper, who saw a wild unicorn in the Maine Woods in 1673" [1]. One can deduce from this reference only that the whole of the tale takes place subsequent or prior to that sighting, as there were no unicorns anywhere in the world, save for the protagonist of the novel, at the time of her quest's initiation.[2]
One could go so far as to speculate that the unicorn seen by Dr. Dapper was in fact the unicorn who briefly became the Lady Amalthea. However, there is no paricular textual evidence to support that identification, nor the possible identification of Dr. Dapper with the elder of the two hunters who appear in Chapter 1. While that character clearly believes in the unicorn's presence, he does not actually see her at all.
On the other hand, there is considerable evidence against the portrayal of the milieu of the The Last Unicorn as an undatable, vaguely Medieval neverland; evidence against the portrayal of that world in the filmed version of the story, in other words. There are a number of references within the text which would be anachronistic in such a pre-modern setting.
Working backwards through the text, one finds the most obvious "anachronism" in Chapter 7, when the protagonists of the story arrive in the town of Hagsgate and are threatened: "Two [men] set their swords at Schmendrick's throat, while another guarded Molly with a pair of pistols." The mention of pistols clearly moves the text out of Medieval times, placing the novel no later than the fifteenth or sixteenth century.
And earlier, in Chapter 6, the protagonists narrowly avoid an encounter with a prince and a princess (later revealed to be Prince Lir and his fiancee) engaged in a unicorn-summoning rite. While the princess begins the rite, "the prince [begins] to read a magazine." Magazines, of course, are hardly common reading material in the Medieval settings; the word only entered the English language in the sixteenth century.
The final two clues not only provide information concerning the date of the story, but firmly tie it to events in that era. When, in Chapter 5, the magician Schmendrick conjures up images (or possibly eidolons) of Robin Hood and his Merry Men, the outlaw Captain Cully attempts to convince his suddenly mutinous band that the images are just that. "`Robin Hood is a myth ... a classic example of heroic folk-figures synthesized out of need. John Henry is another.'" It would be impossible for Cully to refer to John Henry (fl. 1870) before the nineteenth century.
Confirming that estimation, the following exchange occurs earlier in that same chapter:
[Captain Cully] beamed at what Schmendrick hoped was an expression of pleased surprise. "I said there were several stories about me. There are thirty-one to be exact, though none are in the Child collection just at present --" His eyes widened suddenly, and he grasped the magician's shoulders. "You wouldn't be Mr. Child himself, now would you?" he demanded. "He often goes seeking ballads, so I've heard, disguised as a plain man --"
Of course, Schmendrick is not Francis J. Child (1825-1896) and it is unlikely that the Harvard professor ever actually went "seeking ballads" in disguise. Still, the reference clearly places this sequence, and hence the rest of the novel, during the time when Child was publishing his authoritative collection _The English and Scottish Popular Ballads_; between 1882 and 1898.
Is it possible to be more precise? I believe that it is, although I am not at liberty to reveal the source of my evidence allowing greater precision. But that information indicates that the the unicorn was transformed into a human being no more than three months before her final encounter with the Red Bull, and that she had been travelling with Schmendrick and Molly Grue no more than six months before that transformation. It is impossible to say how long she had been searching alone before her meeting with Schmendrick; as Beagle points out, immortal creatures have no sense of the passage of time without mortals to provide a referent.
In any event, I believe that the climax of the novel occurred between sunset on January 2, and sunrise on January 3, in the year 1892; at the same time, roughly speaking, that John Ronald Ruel Tolkien was born.[3]
[1] Lest the reader be skeptical of the possibility of such creatures of "the Old World" surviving in America, I refer her (or him) to a vignette entitled "Then I Wasn't Alone" by Manly Wade Wellman, detailing John the Balladeer's brief meeting with a creature straight out of European myth.
[2] The Irish Rover's lyrical account of the entire species' extinction during the Deluge must be viewed as apocryphal, or possibly a misinterpretation of folklore surrounding the unicorns' actual fate. One might even speculate that the song was inspired by an older one composed by Captain Cully.
[3] Of course, not unlike a particle whose position or speed may be known, but not both, knowing the date of the event gives no clear answer to the question of its location. My own best guess places Haggard's kingdom in the same regions of Eastern Europe where Ruritania, Lutha, Florin and Guilder can be found, and suggests the Adriatic as the sea into which the unicorns were driven. But there is as much evidence to place the desmesne in Brittany, or Cornwall, or even in the regions of America which border the land of Oz.