In Queen Elizabeth’s reign Sir Brian MacPhelim O’Neill usurped the O’Neill estates with the help of the English, but they were shortly afterwards confiscated and bestowed by the Crown on Sir Thomas Smith.
In 1573 there is a memorandum by Secretary Smith offering to give up to the Earl of Essex upon certain conditions “Belfast, Massareen, Castle Mowbray alias Eden Doucarg (now Edenduffcarrick or Shane’s castle, in the county of Antrim) and Castle Toome.”
After the treacherous seizing and execution of Sir Brian in 1574 a fierce struggle for possession of Clandaboy began between his son Shane MacBrian and a cousin, Neal Oge. In 1583 Captain Thomas Norreys captured the castle of Edenduffcarrick from Hugh Oge and handed it over to Shane as Captain of Lower Clandaboy.
A writer about 1586, describing Antrim, states that Edenduffcarrig and Belfast were the only wardable castles at that time.
In 1588-89 Lower Clandaboy was divided between Shane M’Brian M’Felim O’Neill, and Neale M’Hue, son of Hue M’Felim. The latter was granted the castle with a fourth of the country and followers, but as he was unable to provide the pledges required for the safe delivery of the castle and the payment of rent, he was imprisoned in Dublin Castle until he could find them. In the meantime his men garrisoned Edenduffcarrick.
Shane M’Brian O’Neill endeavoured to get possession of North Clandaboy in 1591 for himself and his heirs, and the Government received warning that it would be best for them to keep Shane’s Castle in their own hands, especially as it could be used to guard the fisheries of Lough Neagh, where a “civil English plantation” might be formed.
The same year Shane and his cousin Neale agreed to submit to arbitration regarding the division of North Clandaboy. Commissioners were, therefore, appointed by the Lord Deputy, and Shane’s Castle was reserved to the Crown according to advice.
The Earl of Tyrone formed a camp near the castle in 1593-94, and the Sheriff of Antrim appealed to the Lord Deputy for a guard to be put in Edenduffcarrick, saying that otherwise the country was unprotected, and that it “is the only mark that these fellows shoot at.”
After this the castle seems to have been allowed to fall into decay, for in 1596 Mr. Francis Shane, discoursing about the rebellion in Ulster, states that upon the edge of Lough Neagh “standeth a ruinated pile called Edendowcarrick,” which being made wardable could be converted into a store for provisioning Blackwater and Coleraine in case of sea storms.
Later it was evidently taken possession of by Shane M’Brian O’Neill, who had joined with his great namesake and kinsman, the Earl of Tyrone, for in 1597 Sir John Chichester, with the help of Neale M’Haghe (the other claimant to Clandaboy) took the castle from him. It was a somewhat unexpected victory, as Sir John did not at first intend the capture. He had divided his forces into three companies of a hundred men each. One party he sent to seize some horses of the enemy, the second was detailed to harass the rebels, and the third, which he himself commanded, was intended to prevent a sally from the castle. The garrison did make an attempt to issue forth, and he presently came up “pell mell with them,” and entered the bawn.