What this song renders
The departure and its scale are documented. The Anglo-Saxon Chronicle puts Harald’s invasion fleet at three hundred ships; Heimskringla says ‘over two hundred, besides supply ships.’ After the catastrophe at Stamford Bridge the survivors needed only the saga’s twenty-four hulls to sail home. The magnitude is real — an armada reduced until a fraction of its ships sufficed to carry the living away — and it is the song’s spine.
The arithmetic, though, is shorthand rather than a body count. Many of the ships were the Riccall guard that never fought, and the figures come from different sources counting different things. The track is careful to use the contrast as an image — the unbearable shrinking of a fleet — not as a literal casualty sum, which is the line the album draws between the documented scale and the legend of the count.
Two things are the album’s framing rather than the record’s. That Elisiv was the woman waiting in Orkney comes from Snorri; the older sagas put Tora there instead. And the sight — the second sight that lets her count the ships home before they sail — is the album’s one acknowledged invention, the lens through which the documented departure is seen.
The fleet, the invasion, and the scale of the loss are documented (the Chronicle’s 300 ships, the saga’s 24 home); the literal arithmetic is dramatic shorthand, not a casualty count; Elisiv’s presence in Orkney is Snorri’s account over the older sagas, and the sight is the album’s acknowledged invention.