This medieval residence represented the ecclesiastical power and wealth of the period, when church officials often held significant temporal authority alongside their spiritual duties. The exact location and appearance of this original structure remain somewhat mysterious, though historical records confirm its existence during a time when such fortified residences served both as comfortable homes and defensive strongholds.

Today, visitors to Killybegs might unknowingly pass by the very spot where this medieval manor once stood. Local archaeological surveys suggest that Cat Castle, another historical structure in the area, may actually occupy the same site as Bishop McIlmonagle’s original manor house. This theory, whilst not definitively proven, offers a fascinating glimpse into how medieval sites were often reused and rebuilt over centuries, with newer structures rising from the foundations of their predecessors.

The archaeological record for this site comes from the comprehensive Archaeological Survey of County Donegal, compiled by Brian Lacey and his team in 1983. This detailed survey catalogued field antiquities spanning from the Mesolithic period through to the 17th century, providing invaluable documentation of sites like the Killybegs manor house. Such surveys help piece together the complex layers of Irish history, where medieval bishops’ residences, defensive structures, and later buildings all contributed to the rich tapestry of Ireland’s built heritage.