[5] He has produced monographs on the early history of the Friendly Brothers of St Patrick in Kildare, 1758–91;[6] on the depositions from Kildare on the outbreak of the Irish Rebellion of 1641;[7] and on the Irish Jacobite ancestry of the Mitford family (privately published).
He married, in 1990, Louise Arundel and the couple have four children: Celeste, Tom, Lily and George.
Through his maternal great-grandfather, the 2nd Duke of Urach, he is a potential claimant to the medieval Kingdom of Jerusalem, the Kingdom of Lithuania, to the Principality of Monaco (see Monaco succession crisis of 1918) and to the title of Duke of Estouteville.
[9] Partly because of previous family involvements, he is a trustee of the Iveagh Trust social housing provider, and is a former president of the Irish Georgian Society.
[10] In September 2010, he became a Knight of Justice of the Military and Hospitaller Order of St. Lazarus of Jerusalem at a ceremony in St. Patrick's Cathedral in Dublin.