It was The 4th Earl of Kenmare who decided to build a new mansion on a hillside with views of Lough Leane in 1872.
This house was supposed to have been instigated by Lady Kenmare (Gertrude Thynne, granddaughter of The 2nd Marquess of Bath) and inspired by Lord Bath's genuinely Elizabethan seat, Longleat, Wiltshire (which is not red-brick); but it was not unusual for the descendants of Elizabethan or Jacobean settlers in Ireland to assert their comparative 'antiquity' in this period by building Jacobethan houses.
The house, in addition to its other defects, apparently did not sit happily in the landscape as it had many gables and many oriels.
He and his wife Mary J. Horstmann (1907–1998) extensively renovated the building and renamed it "Killarney House".
In July 2011 Leo Varadkar, then the Irish Minister for Transport, Tourism and Sport, therefore announced a €7 million restoration of the manor.