Sir Allen Apsley, in 1623, made a report of the prisoners then in his custody, in which he said, 'There is here Sir Nial Garve O'Donel, a man that was a good subject during the late queen's time, and did as great service to the state as any man of his nation.

He has been a prisoner here about thirteen years.

His offence is known specially to the Lord Chichester.

Naghtan, his son, was taken from Oxford and committed with his father.

I never heard any offence he did.' While O'Cahan was in prison, commissioners sat in his mansion at Limavaddy, including the Primate Usher, Bishop Montgomery of Derry, and Sir John Davis.