THE BARONY OF RATHDOWN
The importance of Rathdown Castle and village is mirrored in the extensive Barony of Rathdown, which stretched from the Three Trouts river to Merrion Gates in Dublin.
As counties were being established in the early 17th century, the Barony of Rathdown had to be split in two, one Half-Barony in County Wicklow, the other Half-Barony in County Dublin.
The importance of the name Rathdown is emphasised by its use today in organisations such as Dun Laoghaire-Rathdown council.
Smal, Chris (1993) Ancient Rathdown and St. Crispin’s Cell, A uniquely historic landscape, Friends of Historic Rathdown, Greystones.