From: Early Irish History and Antiquities and the History of West Cork By Rev. W. O’Halloran 1916, O’Driscoll Genealogy.

The O’Driscolls of West Cork
The O’Driscolls were not exterminated by the newcomers, and remained independent until the year 1232, when Cormac Goth, third son of McCarthy Mor, acquired dominion over the entire region. To the end of the sixteenth century they still possessed Baltimore, Sherkin and Cape Clear, also the adjoining lands, Kilcoe, Creagh, and Aghdown. Having received little quarter at the hands of Irish chiefs, it is no wonder they became loyal to the English crown.
An English title was bestowed on Fineen O’Driscoll for his loyalty, and he so conformed to English customs, as to take his lands by letter patent from Elizabeth.
The O’Driscolls were almost always engaged in petty warfare, smuggling, pirating, and raiding. It was the custom of the country at the time. During the fifteenth century they and the Waterford people had many an encounter. They were accustomed to visit the city from time to time, for the sake of plunder, and sail home with their ships laden with booty. In the year 1450 it was enacted ” as divers of the King’s subjects had been slain by Fineen O’Hedriescoll, chieftain of the nation, that no person of the parts of Waterford, Wexford, etc., shall go within the country of the said O’Hedriescoll under heavy penalties of forfeiture.”
In 1537, four ships from Lisbon, laden with wine, consigned to the Waterford merchants, were, by stress of weather, driven to take shelter at Baltimore. One of these, the Santa Maria de Soci, was boarded by Conoghure O’Driscoll, chieftain of Sherkin, and his sons, and piloted safely into Baltimore Harbour. The officers and men of the ship were invited to an entertainment to Baltimore Castle by the O’Driscolls, and while there enjoying themselves were manacled. The O’Driscolls and their men went in their boats to the ship, took possession of the wine, and freely distributed it among their followers.
The Waterford people, hearing of the seizure, sent an armed expedition under the command of Captain Dobbyn. On arriving at Baltimore, he liberated the crew, and immediately sailed back to Waterford. Of the 100 tuns of wine, 25 only remained unconsumed. Some short time after, an expedition of 400 men, well equipped, set sail from Waterford in two large vessels under command of Bailiff Woodlock and Captain Dobbyn. Arriving in Baltimore Harbour they anchored near the Franciscan Abbey on Sherkin Island. Very soon they commenced operations, attacked and battered the castle of Dunilong, which they entered, and took away large quantities of malt, barley, and salt; they burned forty of the chief pinnaces, and forty more, with the big galley of thirty oars, were conveyed to Waterford as trophies of war. The Franciscan Abbey, with the mill annexed, was greatly damaged, and the inhabitants and houses of the island were visited with fire and sword, and little mercy shown. The islands near were treated in a similar manner, and, to complete the work, the attacking party passed over to Baltimore, stormed the Castle of Dunashad, and burnt and sacked the town.
In the year 1601, on the arrival of the Spaniards at Kinsale, Sir Fineen joined the insurgents, and allowed his castles to be garrisoned by Spanish soldiers. The insurrection proved a failure, and was fatal to Sir Fineen, but he managed to secure a pardon from Elizabeth, to whom he was fully reconciled on account of the following service. An English fleet happened to be becalmed outside Baltimore. Sir Fineen entertained the officers and men most hospitably, and good wine was distributed so plentifully that it flooded the town. Handfuls of silver were thrown into the well, which supplied diversion for the crews, and up to the present this well retains the name of Tobar-an-arigid. Elizabeth, to compliment Sir Fineen for his liberality to the fleet, summoned him to court. The Queen died before his arrival in London, and Sir Fineen himself soon after died in England.
According to O’Donovan, Sir Fineen let the entire of the Ballymore territory to Sir Thomas Crooke (one of the undertakers) for twenty-one years at a fine of £2,000 sterling, and thus practically laid the foundation for a forfeiture. Sir Walter Coppinger, during his absence in England, intruded on the estate. The matter was contested by Sir Fineen’s heir, and some of the citizens of Baltimore. Coppinger was confined in Dublin Castle for contempt of court, but he granted a lease of the whole territory to Henry Busher, who was one of the commissioners appointed to examine the case. The court provided a crooked devisee, and the O’Driscolls suffered the loss of their patrimony. Shortly after Sir Fineen’s death the senior branch became extinct in Ireland.
One of the Castlehaven branch of the family was colonel of a regiment of James II., and bravely defended Ringroan Castle against the renowned Marlborough. Some members of the family emigrated to Spain and distinguished themselves abroad in a military capacity.
St. Fachna, founder of the diocese of Ross, in the sixth century, was a member of the O’Driscoll race.