In 1600, a "manor" was the mansion of a lord with the land belonging to it - hence, a landed possession; while in 1610, it was defined as "a mansion, a habitation; the principal house of an estate". In 1538, it was "a unit of English territorial lordship. It now consists of the Lord's demesne (if any) and the lands from the holders of which he has the right to exact certain fees and fines, and within which he has certain privileges". These emoluments formed part of the rents and so on from manors in 1296, due to the archbishop of Dublin. One such was the Manor of Coloyne. "£53 13s 5d, fruit, herbage of gardens of S Keyvin's and Coloyne, fishery of Annelyf, Wood of Coloyne, columbaries, meadows, pasture, de bollis cervisiae, Alewortys, work of cottagers, ploeas and perquisites, fines of heriot and other receipts of the Manor of Coloyne and S.Sepulchre - £33 6s 7d sale of wheat. £105 4s 4d rents, including seldae of Nich. Brekeleye, taken after his death into the king's hand. Total £192 4s 4d".
The manor of St Sepulchre, formerly the manor of Colonia, was one of the more important manors. It contained an archiepiscopal palace, and it was in this manor that Archbishop Comyn built the collegiate church of St Patrick and a palace in 1191. Probably from thenceforth his manorial court was held in this palace, though the official change of name does not appear to have taken place until the reign of Edward I (1272-1307). On one Pipe Roll it is called "the lordship of Colonia"; while on another the receipts of the manor were entered as those of "the manor of St Sepulchre with Cullen". A 1326 document, "Inspeximus of an extant of the manor of St Sepulchre", informs: " . . . there is a hall with stone walls, now thrown down, a chamber for the archbishop with chapel adjoining; these are roofed with shingles and of no value . . . there were a kitchen built of timber, a grange, a stable and a granary roofed with 'boords', now altogether thrown down."
In The Calendar of Archbishop Alen's Register, c. 1172-1534, this placename was variously spelt Colonia, Cullen, Colyn, Cullyn and Colon, with a number of references to the "Wood of Cullen". Five hundred of the citizens of Dublin City who sallied out of the walls on Easter Monday 1209 to play a hurling match on the flat land at Cullenswood (beside the modern Sandford Road), were slaughtered when ambushed by local Irish septs. This placename, in its various spelling, mostly stands independently, indicating , perhaps that the first element is not the surname Cullen, but some topographical feature. Cullen names townlands in Cos Fermanagh, Meath, Tipperary and Cork. Those in Cos Cork and Tipperary and Cullion in Co Tyrone derive from cuilleann, an obscure word probably meaning "the side of a hill", not cuileann, "a holly bush", nor the surname Cullen, ╙ Cuilinn, which derives from it.
The Cullens originated in Co Wicklow, though some of the 1,545 Cullen telephone entries south of the Border, and the 190 to its north, may bear the English Cullen. This derives from the local name Cologne, meaning "colony", this being Old French from Latin; or from the German Rhineland city; or possibly meaning "at the back of the river", or from the Scots Gaelic. The vast majority of the Cullen telephone entries are in the south-east of the island, and the single ╙ Cuilinn is in Dublin city.
Taylor & Skinners 1778 Maps of the Roads of Ireland shows Cullen at Skreeny, east of Manorhamilton, Co Leitrim; a Rev Mr Cullen, Cherry Mount, south-east of BallyGrange, near Sligoshannon, Co Donegal; and a Rev Cullen, town. The 1814 Directory shows the Rev William Cullen, Glen Lodge, Leighlinbridge, Co Carlow, and Michael Cullen, Newtownkilbride, Co Kildare. Cullens listed in Owners of Land of One Acre and Upwards (1876) possessed mainly modest holdings in seven Leinster counties - Carlow, Dublin, Kildare, Kilkenny, Wexford and Wicklow, with a sizeable 745 acres in Co Meath. There was a single Tipperary holding of 15 acres, and a single Co Galway holding of 611 acres at Cloonkeen, Kilkerrin. There were very modest Cullen holdings in Cos Armagh and Derry, but the largest were in Co Leitrim - Carncross T Cullen, Glenade House, Manorhamilton, 1,279 acres; Hester Jane and sisters, Glenade House, 2,210 acres; Henry Cullen, Corry Lodge, 630 acres; and William Parke Cullen, Cloonkeen, Co Galway, 1,369 acres.
The Irish for Cullenswood is Fiodh Cuillinn (fiodh, wood, timber, cuilleann, the side of a hill).