THE PLAIN OF THE BOYNE I. original: BRUG I.

25 The grave of the Mata original: Máthai. The Mata was a legendary multi-legged monster or dragon of the Boyne Valley said to have been slain at the "Stone of the Mata" near Newgrange. after it was slain
is clearly upon you, O Brug, where the horse-herds are dappled;
one of its bones defiled the sea,
from which fair Inber Colptha original: Inber Colptha. The estuary of the River Boyne at Drogheda; legend says it was named after Colptha, son of Míl, or from the "colptha" (shin-bone) of the Mata. is named.

The hide of Boadan’s enduring cow
30 lies over the slope of his yellow-white stone;
the sanctuary of the faithful, keen Fian-warriors original: Fían. The legendary bands of semi-independent warriors, most famously led by Finn mac Cumaill.
surrounds the eastern plain of noble Nemed. Nemed was a mythical leader of one of the early groups to inhabit Ireland.

At the Mounds of the weak Seagulls, original: Fertai na Fáilenn. A specific location within the Boyne complex.
it was there the great exploit was achieved;
35 a great deed of pride by the spear-point
was the slaughter by fierce Finn Finn mac Cumaill. that quelled the Luagne. The Luagne were a warrior tribe of ancient Meath often in conflict with Finn.

A pleasant son was born within you,
Cellach, Cellach was the son of Cormac mac Airt, a famous High King. who plundered the plain along his track;
he was fit to lead a household, yet you held him fast,
40 until he died a death of pride upon you.

O prow-shaped fortress original: barc brainech. Likely referring to the ship-like appearance of the mounds or their role as a "vessel" for the dead. of the heavy towers,
the sea-wave visits your stronghold;
from the time of Crimthann Nia Náir to Niall, Crimthann Nia Náir and Niall of the Nine Hostages were legendary High Kings of Ireland.
you were the cemetery of the fair warriors.

45 Fintan Feradach of the bloody journey
possessed your heavy earth;
Tuathal Techtmar, Tuathal "the Legitimate," a foundational figure in Irish kingship. lord of our clans—
your bare, grave-filled ground supports him.

The following section preserves scholarly notes on manuscript variations (LU = Lebor na hUidre; B = Book of Ballymote; M = Book of Ui Maine; S₂ = Stowe Manuscript).

25. Grave] hill in LU. Mata] in LU; mata, etc. in others. after it was slain] on the plain of Uin in B (corrected by a later hand to after it was slain); on the plain in S₂; on the high plain in M.
26. clearly upon you] LU; from the fort in S₂; upon you, etc. in others. the] in S₂. Brug] plain in H.
27. its bone] LU; it is its bone, etc. BH; it is his bone in M; six bones in S₂. did] omitted in M. defile] help (corrected by a later hand to defile) in B; defiled in HS₂.
29–40] These lines appear in LU only.
31. faithful] faithful in LU.
32. plain] plain in LU.
33. seagulls...