Terence O'Brien (bishop)

After a drumhead court-martial, he was hanged by order of General Henry Ireton at Gallows Green, officially for advising against the surrender of the city, but in reality as part of the religious persecution of the Catholic Church in Ireland that began under Henry VIII and ended only with Catholic Emancipation in 1829.

Bishop O'Brien was beatified as one of 17 Irish Catholic Martyrs by Pope John Paul II on 27 September 1992.

Both of his parents were from the derbhfine of the last Chief of the Name of Clan O'Brien Arradh and claimed lineal descent from Brian Boru.

Along with Alderman Thomas Stritch and English Royalist officer Colonel Fennell, Bishop O'Brien was tried by a drumhead court martial and sentenced to death by New Model Army General Henry Ireton.

There are various anecdotes about his demise from Irish ecclesiastical and English Royalist sources, by whom Ireton's death has been depicted as divine retribution for the hanging of Bishop O'Brien, who prior to his death had called upon Ireton to answer at God's judgment seat for the New Model Army's massacres.

For example, the Hibernica Dominicana claims that on his death bed, Ireton was "privately muttering to himself, 'I never gave the aid of my counsel towards the murder of that bishop; never, never; it was the council of war did it...

"[11] In contrast, the memoirs of English Cavalier officer Philip Warwick allege that, in his delirious state, Ireton's last words were, "Blood!

A letter written in 1656, quoted by Lingard, puts the number at 60,000; as late as 1666 there were 12,000 Irish slaves scattered among the West Indian islands.

"[14] After taking the island in 1653, the New Model Army turned Inishbofin, County Galway, into a prison camps for Roman Catholic priests arrested while exercising their religious ministry covertly in other parts of Ireland.

[17] On 27 September 1992, O'Brien and sixteen other Irish Catholic Martyrs were beatified by Pope John Paul II.

June 20th, the anniversary of the 1584 execution of Elizabethan era martyr Dermot O'Hurley, was assigned as the feast day of all 17.