That earlier settlement grew up along the River Goul, hemmed in by bogland to the east and west, and it carried borough status, a significant designation that marked it as a functioning administrative and commercial community in the medieval period. Its name shifted considerably across the centuries, appearing in documents as Aghnyrle, Aghnenorlyn, Aghenenowrling, and several other variants, the spelling drifting with each scribe who set it down.

The documentary record offers a surprisingly detailed picture of how this place was governed and traded. A 1356 entry in the Ormond Deeds records John, son of William Druhull knight, surrendering his right to collect 40 shillings and threepence in annual rent from his burgesses at Aghnirle, paid in two instalments at Easter and Michaelmas, to Maurice son of Walter Purcel. By around 1399, the settlement was being assessed for knights fees owed to the King, listed at a quarter of a fee. The same obligation appears again in 1419 and 1423. In 1527, Piers, Earl of Ormond, quit-claimed all his right in Aghnenorlyn to two chaplains, Sir John Tobyn and Sir Nicholas Mothyng, and by 1566 to 1567 the name still appears, now listed among ploughlands in the Ormond Deeds. The physical layout of the settlement reflected its complexity. A medieval church and graveyard sat on the north bank of the Goul, while a tower house and its bawn, a walled or enclosed courtyard typically used for defence and the protection of livestock, occupied the south bank. A fording point connected the two sides, and earthworks marking former settlement activity survive both north of the church and south of the tower house. The Down Survey of 1655 to 1656 adds further texture, recording a watermill, the castle, and a structure described simply as a thatched house on the southern side of the river, a small domestic detail lodged inside a century of upheaval.