[1] Murrough was a lineal descendant of Brian Boru, High King of Ireland, and was the third or fourth son of Turlough O'Brien, Lord of Thomond (d. 1528), and Raghnailt, daughter of John MacNamara.

Conor had made a vain endeavour to divert the succession to his children by his second wife, Ellen, sister of James Fitzjohn Fitzgerald, fourteenth earl of Desmond, and there had been, in consequence, much dissension between the brothers.

Conditions of peace and submission were propounded to him; but, as these included the restriction of his authority to the west of the River Shannon, and other stipulations affecting his clan as well as himself, he asked time for deliberation.

[3] He appeared to St Leger "a very sobre man, and very like to contynewe your Majesties trewe subjecte";[3] and Henry, gratified by his submission, expressed his intention of conferring on him some title of honour, together with a grant of all the suppressed religious houses in his country.

This ingenious solution of a perplexing problem clearly demonstrated Henry's intention to proceed in the reconquest of Ireland by conciliatory methods, if possible; he hoped that time would bring with it a practical reconciliation of the laws and customs of the two countries.

He died in the following year and was succeeded by his nephew Donough, who surrendered his patent, and was granted a new one on 7 November 1552, conferring the title on him and the heirs male of his body.