The Earl of Marlborough had returned to England, immediately after the surrender of Kinsale; and General Ginckle, who had now succeeded to the command, determined to harass the enemy, and to increase the resources at his disposal by an expedition into the southwest of Ireland, which, covered by Cork and Limerick, had hitherto been free from the presence of any English troops.

He therefore pushed a strong body of cavalry and infantry westward from Cork and Kinsale; and these succeeded in making themselves masters of Castle Haven, Baltimore, Bantry, and several other castles on the line of coast.

The district was wild and mountainous, and the passes might have been easily held against the advance; but the peasants had not been organized for resistance, and no serious opposition was encountered.
Colonel O'Driscol, a cousin of MacFinn O'Driscol, and Captain O'Donovan, two of the principal proprietors of the neighbourhood, soon arrived upon the spot, and assembled a large irregular force, consisting chiefly of mounted peasants; and with these they soon cooped the invaders up in the castles they had taken.

O'Driscol next attempted the recovery of his own Castle Haven, which was strongly defended, and stood on a cliff overhanging the sea; but his wild peasants were ill adapted for such work, and they were repulsed by the English garrison, and O'Driscol himself killed.

But another force was advancing from the north.