The most ancient days of the Realm, when the Stewards walked the earth and tended the many worlds of Story, have been separated from us by the event known as the Great Unweaving.
Much about this time in the Realm’s history has been lost, but most loremasters and enigmatists agree that the Great Unweaving was brought about by the war between the Stewards and the Night King, Malabron. Naming himself the Lord of Story, Malabron attempted to draw the threads of every tale into his own, so that if he was victorious the realm of all stories would contain only one story, his own, a nightmare of endless grey sameness and despair.
Along with their allies the Tain Shee and others, the Stewards resisted Malabron’s campaign of conquest and destruction. But as these two mighty opposing forces clashed, the weave of things was warped and twisted and torn out of its harmonious shape. Gaps and holes appeared, stories fell into darkness or were changed into bleak and violent versions of what they had been. It was in this lost age that storyshards first appeared.
Even time itself was affected by the Great Unweaving, and this is why we cannot be sure how long ago these events happened. Loremasters call the ages between the Great Unweaving and our time the Broken Years, because time itself was literally broken. Seasons no longer followed their ancient cycle (in some places winter might last for years, or summer would draw on so long that crops would wither and rivers would dry up). All the ways in which people counted and measured time became faulty and unreliable, and so there is a gap, a blank space, in all histories and almanacs between the ancient days and more recent times. Those who tend to such matters dated the New Era from the moment that the star known as the Great Waylight first appeared in the night sky, and from that event began a new count of years. Their dating became the Realm standard, and by its measure, for example, the year that Will Lightfoot first came to the Perilous Realm was the year 2021 of the New Era.
Some inhabitants of the Realm, like the Tain Shee, live far longer than mortal folk like you and I. The Shee may in fact have been immortal before the upheaval of the Great Unweaving. All they will say about the days before their war with Malabron is that “time was much wider and deeper than it is now. A moment was a lifetime.”
Even the lifespan of the Shee, then, was changed by the Broken Years, and although they still appear to have some power to slow the passage of time, they can grow old as we can. Moth and Morrigan, the Shee whom Will Lightfoot met and befriended, seemed to him both young and ancient at the same time. One can be certain that they (as well as Shade the wolf) are older than 2021 years, but how much older, no one can say, for the Shee do not measure the years before they stood with the Stewards to defy the Night King (at least not as we measure them).