The fortress seems to have been built soon after the Norman invasion, and as the lands of Dundrum were held by Hugh de Clahull, it was probably erected for their defence. It subsequently passed to the Fitzwilliams of Merrion, from whom it descended to the Earls of Pembroke, and it forms at present part of the Pembroke estate. Robert le Bagod, ancestor of the Fitzwilliams, had license to convey the manor of Dundrum to his son William, and in 1332 Thomas Fitzwilliam was found seized of the lands round. From this time on it is likely the fortress was occupied by cadets of the Fitzwilliam family. In 1542 Sir Thomas Fitzwilliam was in possession of the manor, and in 1616 his grandson Thomas, afterwards first Viscount Fitzwilliam, recovered the lands of Dundrum and Ballinteer, with the castle and water mill. His brother William, who had married Archbishop Ussher’s widow, lived at Dundrum Castle about this time. The building was slated and in good repair during the Commonwealth. It is stated to have had three hearths and a barn, with a garden. It was tenanted by a Mr. Isaac Dobson during the reign of Charles II. He was a Nonconformist, and probably a trader in Dublin. When James II. came to the throne he left the country, and was attainted by Parliament in 1689. His son, who was a bookseller, succeeded him at the castle. He greatly improved the grounds, and when he died in 1720 he left the use of the castle to his wife for her life, after which it went to his sons. The last Dobson who lived in it died in 1762, and when Mr. Cooper visited it in 1780 it was most likely inhabited by a farmer, who was then cutting down the grove of ash which grew between it and the river. He speaks of the inhabited part as a modern addition to which older remains were adjoining. He states that the principal entrance was from the courtyard by stone steps. It soon afterwards fell into ruin, and at the beginning of the nineteenth century the present modern dwelling-house was erected. This was at first inhabited by the Walsh family, and later Dr. Reichel, Bishop of Meath, lived in it. Miss Hume is the present occupier. AUTHORITIES CONSULTED. E. Dix, “Dundrum Castle,” in “The Lesser Castles in the County Dublin”; F. Ball, “Dundrum Castle,” both _Irish Builder_. Ball and Hamilton, “The Parish of Taney.” [Illustration: DUNLUCE CASTLE.] _DUNLUCE CASTLE_ The ruins of this stronghold are picturesquely situated upon a rocky promontory about three miles east of Portrush, in the County Antrim, which is divided from the mainland by a chasm 20 feet wide and 100 feet deep. The name Dunluce, or _lis_, signifies “strong fort,” and in all probability the castle is built on the site of an ancient _lis_.