It is said that it was Isabel, Countess of Pembroke who was responsible for the building of the church of St. Mary's New Ross.

Positioned high above the town, and of unusually large dimensions, it was the grandest of the early Irish gothic churches. It's cathedral-like presence reflected the level of importance attached to the town itself.

A heart shrine, possibly of Isabel's remains within the church.

In the panel, William Marshal can be seen, mounted and perusing some draft drawings, aided by a scholastic monk (William Marshal, in common with all Norman knights was illiterate). Artisans and stone carvers are working on the dogtooth decorations and disembodied heads for the church interior. Isabel leans over a mapping table, but towering above the busy scene, the spirit of Dermot who says "I did this". The upper borders show scenes from the lives of the much revered early Wexford saints, St. Ibar sheltering in a tree, St. Fintan who used wolves to guard his sheep while he studied, St. Abban who had control over the waters and favourite of all Aidan or Mogue after whom many Wexford children are named.

The lower border shows Dundry stone being taken from Bristol ships berthed at the port of Ros and brought by oxen up St. Mary's Street for the building of the church. A party of huntsmen return from Old Ross, where around the motte and bailey Norman farms thrived and a deer park was established.