[4] Ardamullivan Castle was built in the 16th century by the Uí Sheachnasaigh (O'Shaughnessy) clan, rulers of the region known as Cenél Áeda na hEchtge until being disposed by Cromwell's invasion (1650s).

In 1579, Diarmaid Riabach Ó Seachnasaigh and his nephew John, fought each other in a dispute over the castle, which resulted in death for both.

[6] Diarmaid Riabach had previously acquired notoriety after betraying Richard Creagh, the fugitive Catholic Archbishop of Armagh, to the authorities.

[8] Late medieval wall paintings were discovered on the first and fourth levels;[9] they have been compared to those at Abbeyknockmoy and Clare Island Abbey.

Depicted is a bishop, a stag hunt, Saint Christopher, a Passion cycle,[10][11] and St Michael weighing souls on Judgement Day.