The names of streets and roads in towns and cities change sometimes to commemorate a person or patriot, or because of some previous "bad repute". Dublin's Exchange Street was so named in 1776 because of its proximity to the newly built Exchange. It had been Blind Quay (although not on the river) in 1639 and before that Isod's Lane, and as far back as 1293 was called Scarlet Lane.
The Calendar of Inquisitions (Margaret C. Griffith, Irish Manuscripts Commission, 1991) notes a hearing of November 6th, 1577, regarding "an encroachment on Dublin streets". "There is another street, now concealed, called Scarlet Lane, running from Wine Tavern St to Fish Shamles Square. The Winetavern St end is blocked y a house lately built by Nicholas Barrow, baker, & now occupied by Patrick Cosgrove, baker, & the other end by a paling."
The Court Book of the Liberty of Saint Sepulchre notes that in 1586 a dispute arose between Nicholas Coscro, baker, and Annam Herfforde, apud Tholoneum Dublin; that William Cosscrowe was one of two present at the "sealing a' deliveri hereof & also at liverie and seizon is taking of the sayd lands . . ." (Colmanstown) in 1580, and that John Coskro de Little Cabbragh was among the jurors of Finglas in 1590.
Thomas Cosgrave was one of Dublin's two sheriffs in 1572, becoming mayor in 1584. The Lords of Dublin in the Age of Reformation notes he was a creditor of the state government in 1585, together with Sarsfield, Fyan, Pentony, Handcock, Sedgrave and others. He was one of those frequently described as merchants, who could have qualified, being a substantial rentier, for the appellation of gentleman.
Topographical Poems says that O Cosgraigh was Lord of Cuala in Leinster, with another sept being Lord of Fir Rois. This latter later became the Co Monaghan Barony of Farney, and the Co Monaghan barony of Ardee, where the counties of Monaghan, Louth and Meath meet. Annala Rioghachta Eireann/Annals of the Four Masters notes the death of O Cosraigh, distinguished bishop of Cluain-micNois in 997; the killing in 1152 by the son of Cronn-Luachra O Cosrachain of Cathal, son of Toirdhealbhach Ua Conchobhair, and the death in 1506 of Tomas Bui mac Cosraigh, erenagh of Clones.
Anglicised forms of the name are found in The Irish Fiants of the Tudor Sovereigns (1521-1603). David Coskeroo of Twowym, alias mcHee, was charged with the death of Margaret Howke in 1551; Ony McCosegrave was among the pardoned - possibly in Co Offaly - in 1559, and in 1556 Christopher Coskrowe, merchant of Dublin, was robbed of £100. Donagh and Agholie McCossrichan were among the pardoned in 1602. They were of Maginnesse country, the Co Down barony of Iveagh in 1602.
Was it Dr Samuel Johnson who remarked that the Irish were a very fair people in that they never spoke well of each other? It would appear otherwise going by early first names: Acobhran, "desirous"; Amhra, "very wonderful"; Adhnar, "very modest"; Aoibhgreine, "radiance of the sun, ray of sunshine". Cosrach, the name of a ninth-century scribe, means "triumphant, victorious". This first name gave rise to the modern surname O Coscraigh in the south-east of the country, to O Coscair in Connaught, and to Mac Coscraigh, Mac Giolla Coscair, and Mac Cosrachain in Ulster. The anglicised forms are Cosgrave and Cosgrove.
Persons of the name Cosgrave/Cosgrove did not accumulate any great wealth going by Owners of Land of One Acre and Upwards (1876). The best-off was Frederick Cosgrave, Rutland Street, Dublin, who had 152 Co Dublin acres, and a further 241 acres in Co Meath. The Rev Thomas and William A. Cosgrave, Eccles Street, had eight and 235 Co Dublin acres respectively. Next highest was Elias Cosgrove, Ringwood, Newcastle, with 145 Co Limerick acres. There were two small Cosgrave holdings each in Cos Wexford and Armagh, and eight acres in Co Antrim.
Current telephone directories south of the Border list 255 Cosgrave entries - 104 in the 01 area, 58 and 33 in the 05 and 04 areas, and 30 in the 06 area. Cosgrove features 312 times - 93 in the 09 area, followed by 69 in the 04, and 67 in the 01.
Today Exchange Street is called Sraid Iosoilde in Irish. Dublin Street Names (C.T. McCready 1892, reprinted 1987 by Carraig Books Ltd.) says that Isod's Lane was so named from "its proximity to Isod's (or Issolde's) Tower, situated on the city wall near Cork-hill."