I found this interesting
This Munster county is the largest in Ireland.The major towns in the county
are Cork city, Mallow, Mitchelstown, Youghal, Kanturk, Cobh, Fermoy, Kinsale,
Clonakilty, Skibbereen, Bantry, and Bandon.
Before the establishment of the county system, the area of the present County
Cork was divided between the territories of Desmond, Muskerry, and Corca
Laoidhe.The major Gaelic families in the county were McCarthy, O'Keefe,
Murphy, O'Mahony, O'Callaghan, O'Donovan, O'Driscoll, and O'Riordan.
The city of Cork itself was founded in the sixth century by the establishment
of a monastery and school on the site by St. Finbarr. This grew into a
considerable town.In the early ninth century the Norse Vikings raided and
later settled in the town, establishing it as a trading post, and merged with
the local inhabitants.
Following the Norman invasion in the twelfth century, the county was granted
to the Norman knights, Fitzstephen and De Cogan. These brought over further
Anglo-Norman settlers, but the colony never extended much beyond the area
around the present Cork city. Like the Norsemen, the Normans in the county
gradually merged with the native Irish and adopted the Irish way of life.
Gradually over the succeeding centuries the power and holdings of the
individual Norman families increased by war and intermarriage.The main
names of Norman extraction now found in the county are Barry, Roche, Cogan,
and Nagle.The Anglo-Saxon names of Gould and Verling are also found in Cork
Hope it helps understanding the Cork