This name is found in all the provinces of Ireland but is common only in Ulster, where it is strongest in counties Down, Derry and Antrim.  It is also well known in Dublin.  It has been recorded in Ireland since early medieval times but its current prevalence in Ulster probably stems from post-Plantation Scottish settlers.

The name is Norman, originally le Mareschal.  It stems from the Old French mareschal, meaning a 'farrier'.)  Although the position of marshall became one of great dignity, it is though that, in Scotland at least, the majority of Marshalls derive their name from the more humble occupational name.  A particular concentration of the name was noted north of Newry in Co. Down in the late nineteenth century.



Clan From the Gaelic clann which means literally 'children'.
Mac- From the Gaelic mac, meaning 'son'
O' From the Gaelic , meaning 'grandson', 'grandchild' or 'descendant'; N is the femine form of , meaning 'daughter' or 'descendant'
Plantation (Ulster) The redistribution of escheated lands after the defeat of the Ulster Gaelic lords and the 'Flight of the Earls' in 1607.  Only counties Donegal, Derry, Tyrone, Armagh, Fermanagh and Cavan were actually 'planted', portions of land there being distributed to English and Scottish families on their lands and for the building of bawns.
Sept A family group of shared ancestry living in the same locality
Undertakers Powerful English or Scottish landowners who undertook the plantation of British settlers on the lands they were granted.
Gaelic This word in Ireland has no relation to Scotland.  As a noun it is used to denote the Irish language, as an adjective to denote native Irish as opposed to Norman or English origin.
Erenagh From the Irish Gaelic airchinneach, meaning 'hereditary steward of church lands'.  A family would hold the ecclesiastical office and the right to the church or monastery lands, the incumbent at any one time being the erenagh.