Taylor & Skinners Maps of the Roads of Ireland (1778) shows Gaffney Esq, at Salled Hill, over a mile north of Kilcullen, Co Kildare. Lieut Alexander Taylor's 1783 A Map of the County of Kildare shows Silliott, a residence on the right side of the road as one travels north, with, on the other side, an eminence whereon sits a tree-encircled round fort named Rath Gaffney. Salliott-Hill is in the 1814 Directory, with Silliothill in the Index of Townlands (1851).
The Gaffneys of Silliothill may have been either O Gamhna (gamhain, calf) or O Caibheanaigh, the names of two south Leinster septs, or Mac Carrghamhna (calf-spear, a personal name), the name of a midland sept.
The surname Gaffney, according to MacLysaght's Surnames of Ireland, is one of the most confusing of all Irish surnames as anglicised. It may be the "English" of any of the above three, or it may represent Mac Conghamhna or Mag Fhachtna. Presumably, the sound similarity of the first element of Caulfield with "calf" gave rise to O Gamhna being additionally anglicised Caulfield.
Mac Carrghamhna is also rendered MacCarron and O'Growney, and O Caibheanaigh may also appear as Keveny, though not to be confused with the Connaught-Keaveneys. The Census of 1659 lists Gaffney among the principal Irish names of the Co Kildare barony of Carbury, and in the Co Longford barony of Granard.
Selliothill names a townland, divided between the parishes of Carnalway and Moone, which parishes are respectively in the Co Kildare baronies of Naas South and Offaly East. It was rendered Selyot in a grant in 1302, according to Archbishop Alen's Register.
Among the lands granted to James Butler in 1537, as listed in the Ormond Deeds, was the castle of Silliat, Co Kildare, and in a document dated 1546 in the same source this is spelled Sellat. Among the lands granted to William Eustace in 1592, according to a fiant of that year, was the land of Silliotehill.
The Co Kildare book of the Civil Survey (1654) shows Maurice Eustace and Jeoffry ffay of Herberstown sharing 120 acres at Silledhill. The Census of 1659 lists Robert Braghall, gent, as Titulado of Rahangan, listed in the column immediately below Sillott.
MacLysaght's More Irish Surnames gives this surname as Broughall/Broughill/Brohal, informing that in the innocent past this was rendered Brothel in Co Sligo. The earliest reference was to Robert Brohale, a Co Waterford juror in 1312; Philip Brohale was resident in Co Carlow in 1356; in 1402 John Brohale was assessor for the barony of Moone; while one of the same name was assessor in the Barony of Narragh in 1420.
A fiant of 1584 mentions Conor O Brotall; the 1659 Census shows Richard Broughall as Titulado for the Co Dublin barony of Castleknock; and in 1714 Robert Broghill was brought to court as a Papist under the Penal Code.
Though de Bhulbh's Sloinnte na hEireann/ Irish Surnames mentions MacLysaght's uncertainty as to the derivation of this surname, he unquestioningly gives Woulfe's assertion (Sloinnte Gaedheal is Gall) that this name derives from O Bruachail. MacLysaght points out that if we take birth registers of several years in the last century as a guide we find the name mainly in Co Kildare.
One cannot ignore the similarity of Braughall and Broughall but we cannot say whether it was this similarity which led to "Braughall" in the Index, and "Broughall" in the text of Charles Chenevix Trench's Grace's Card. When the aristocratic guard withdrew from the Catholic Committee in December 1791, the leadership was left in the hands of "the Dublin merchant gang of four" - John Keogh, Edward Byrne, Anthony Dermot and Thomas Broughall (c. 1730-1803). None of this name had any land in 1876 as shown in Owners of Land of One Acre and Upwards, but there was a 300-acre Gaffney holding at Ballybrack, Co Kildare.
The Irish for Silliothill is Cnoc Solchoid.