Killeen Castle has been standing in the heart of Royal Meath for over eight centuries, serving as the strategic castle defence system for north Leinster since its construction in 1181 by Hugh de Lacy.
For more than five hundred years, from 1403 until the 1950s, the castle was the seat of the Plunkett family, Earls of Fingall, making it exceptional by any standards. The Plunketts were amongst the oldest of the great Anglo-Irish families and were Ireland's premier Catholic Peers. The castle has been home to distinguished parliamentarians, decorated soldiers, and a Deputy Lord Lieutenant of Ireland from the Plunkett family. Originally, the castle was a series of strong towers with a simple walled enclosure.
Over time, it developed into a fine medieval tower house, gracing the "lordship of Killeen." The nearby village grew, markets were held, and Killeen Castle became the focal point for an entire community. However, from the late seventeenth to the late eighteenth centuries, the castle became dilapidated as the Earls were absent due to various uprisings and natural unrest.
In the early nineteenth century, the 8th and 9th Earls hired renowned architects, Francis Johnson and James Sheil, respectively, to modernize the castle, creating the design for the building that stands today. Johnston is well-known for his work on Dublin Castle's Chapel Royal, the General Post Office, and the Parliament House (now the Bank of Ireland). James Sheil worked on Corke Lodge near Bray and has been attributed to Rathaldran near Navan.
Adjacent to the castle stands the fifteenth-century parish church of Killeen, dedicated to the Nativity of the Blessed Virgin. It was originally part of an abbey complex, which has now disappeared.
