The earliest records of this rectangular fortress date back to 1562, when it was granted to William Vernon. Just eight years later, ownership passed to Nicholas White, and by 1654, the Civil Survey recorded that the property, then known as ‘Black Castle’, formed part of the Earl of Kildare’s extensive lands.

The castle itself is a modest but imposing structure, rising four storeys high with internal dimensions of approximately 7.5 metres east to west and 6.5 metres north to south. Its walls, roughly 65 centimetres thick, have stood the test of time, though a cellar beneath is said to exist but remains sealed off according to the current owner. A modern single storey extension has been added to the south side, reflecting the building’s ongoing use as a residence.

By the early 1900s, Black Castle had undergone such extensive modernisation that contemporary observers noted it had become almost unrecognisable as a historic structure, appearing instead as an ordinary residence to all but those intimately familiar with the area. Today, the castle remains inhabited, serving as a private home whilst quietly preserving its connection to centuries of Leixlip’s past; a reminder of the Norman and Anglo Irish families who once controlled these lands along the Liffey.