The structure appears in the Down Survey of 1654-57, which recorded ‘a Ruined Castle’ at Mondrehid and Eglish in the parish of Offerlane. Even then, over 350 years ago, the castle was already in ruins. The survey’s accompanying map depicts what appears to be a tower house, a common type of fortified residence built throughout Ireland from the 15th century onwards.

The castle’s ownership tells a story of changing fortunes in 17th-century Ireland. In 1621, it formed part of John Fitzpatrick’s estate, as recorded in an inquisition post mortem from the reign of James I. By 1641, according to the Down Survey, the lands of Mondrehid and Eglish had passed to both the Duke of Buckingham and one Teige Fitzpatrick, suggesting a divided ownership that was common during this turbulent period of Irish history. The Fitzpatrick family were prominent landowners in the region, and this castle likely served as one of their defensive strongholds.

Today, little remains of what was once a substantial structure. Only fragments survive: a section of wall measuring 14 metres long and 5 metres high, built from roughly coursed rubble limestone and running northwest to southeast, including the northwest corner angle. There’s also a fragment of the southwest wall’s base, extending about 8 metres. These featureless remnants offer few clues to the castle’s original appearance or internal layout, but they mark an important historical site where the Fitzpatricks once held sway over this part of Laois.