The castle first appears in records during the Elizabethan era when, in 1586, a royal pardon was granted to Donell McTeig McDonoghe of Castledrom. Two years later, Queen Elizabeth granted Donell O’Moriarty and his son Owen a lease for extensive lands including Castledrum’s four ploughlands, along with additional territories in Killemardusak and other areas. These lands had previously been held under the rebellious Earl of Desmond, requiring an annual rent of £15 1s, a considerable sum that hints at the property’s value and the family’s standing in local society.

The castle’s military importance became dramatically clear during the 1641 Rebellion when Donnell McMoriertagh of Castledrum led local gentry and freeholders in the siege of Tralee Castle and town. According to contemporary depositions, they arrived ‘in a rebellious and hostile manner with colours flying’ on 2nd February 1641, with Captain Donnell subsequently taking possession of properties in Tralee itself. The castle’s involvement in these wars ultimately led to its destruction; local tradition holds that it was taken by Cromwell and, ironically, given back to one of the Moriartys, though by then it lay in ruins.

By the 19th century, little remained of this once formidable fortress. John O’Donovan, surveying the area in 1841, found only ‘a heap of rubbish overgrown with grass’ about three quarters of a mile east of Kilgarrylander church. Today, even these remnants have vanished from the pastoral landscape overlooking the River Groin, though the castle’s stones live on, incorporated into walls, gate posts and house pillars throughout the townland; a fitting dispersal for a structure that once commanded such local prominence. The owner of nearby Keel House confirms that much of the castle’s masonry was recycled in this practical fashion, ensuring that whilst Castle Drum itself has disappeared, its substance remains woven into the fabric of the local countryside.