[3] The original construct, together with the nine-arched bridge over the River Barrow formed the main landmarks of the town; and the construction of the castle, in itself creating a place of importance has been credited as a key cause in the development of the town of Leighlin-Bridge.

[6] During the 1590s O'Neill rebellion (see Nine Years' War ) the castle was repaired and re-garrisoned for the crown.

[4] During the Irish Rebellion of 1641 the castle was initially garrisoned by the Catholic confederation, and in 1647 and 1649 was used as a rallying point by the Maquis of Ormond.

[4] A more modern analysis of the Black Castle classifies it as a three-story limestone tower house, with the lowest story vaulted, with the roof enclosed by walls with mural passageways.

Both the tower and the surrounding rectangular bawn have artillery openings, and are architecturally indicative of a 16th-century building.