Teige MacCormac Carty signed an indenture of allegiance to the English laws in 1542, and this was faithfully adhered to by his descendants, who, unlike the other great Irish septs, never went eagerly into rebellion. At this time the clan could raise three thousand fighting men. His son Dermod was knighted in 1558.
The Manor of Blarney, Twhoneblarney, the entire country of Muskerry, with all its lordships and possessions, were granted to M‘Dermod to hold by military service in 1589.
His cousin Charles, however, was page to Sir Walter Raleigh, and through his interest procured from the Privy Council a sequestration of the rents.
In 1596 Cormack M‘Dermot M‘Carthy asked for a new grant of the Manor of Blarney with a release of all conditions.
When war broke out, although Lord Muskerry remained with the English forces, he was seized as a traitor (1600) because his brother had joined the rebels, and a relative informed the Council that he himself was plotting against them.
Tyrone at this time encamped with all his forces near Blarney, which is described as one of the strongest castles in the province of Munster, “for it is four piles joined in one, seated upon a main rock, so as it is free from mining, the wall 18 feet thick, and flanked at each corner to the best advantage.”
Sir Charles Wilmot and Captain Roger Harvey endeavoured to surprise the garrison after the arrest of Lord Muskerry, but the warders, suspecting their motive, made them partake of the food they asked for, outside the castle walls.
When Lord Muskerry was put upon his trial he indignantly denied the charges made against him. The President replied that he had better either confess his guilt and ask pardon, or deliver up Blarney Castle until the accusations were proved false. This Lord Muskerry hesitated to do, and so was committed to prison. At length he consented to give up Blarney to Captain Taafe, on condition that it would be restored to him unaltered.
Shortly after this he escaped, in 1602, but seeing the struggle against the Crown was hopeless, he asked leave to make submission to Sir George Carew, which was granted.
In 1628 he was created Baron of Blarney and Viscount Cartie of Muskerie, and as such went to Parliament.