Until 1976, the ancestral seat of the family was Malahide Castle, close to the village of that name, north of Dublin, Ireland.

With their superior armour and weapons they quickly captured Dublin, forcing the Danish king, Hamund MacTurkill, to retire to his lands in Kinsaley.

Among the invading Normans was Sir Richard de Talbot, a young knight from Shrewsbury but of French descent.

He served his master, King Henry II, well in the invasion of Ireland and was rewarded with a grant of lands around Malahide about 1185.

In 1475, his descendant had his standing further enhanced when King Edward IV conferred the title ‘Lord High Admiral of Malahide and the Seas Adjoining’ with an entitlement to customs dues.

When he died the titles passed to his eldest son, the fifth Baron, who married firstly Emily Harriette Boswell (d. 1898) and then Isabel Gurney, an English philanthropist.

Two of Lady Talbot of Malahide's brothers are also notable: Hugh O'Reilly took the surname of Nugent and was created a baronet in 1795 (see Nugent baronets), while Andrew O'Reilly was a General der Kavallerie in the Austrian Army and made a Count of the Austrian Empire.