MacGeoghegan, Anthony (Niall) (d. 1664), Roman catholic bishop of Clonmacnoise and Meath, was the grandson of Conla MacGeoghegan, lord of Moycashel. The MacGeoghegans were a powerful midlands Gaelic clan; Anthony's brother held over 4,000 acres in Co. Westmeath and his cousin Ross MacGeoghegan (qv) was bishop of Kildare. After being taught by the Franciscans at Multyfarnham, Anthony studied philosophy at Louvain and then theology at Prague and Louvain. He joined the Franciscan order and was ordained a priest on 21 September 1624 at Louvain. Back in Ireland, he impressed his superiors with his learning and ability, and was appointed guardian of the newly re-established Franciscan house at Athlone, Co. Westmeath, in 1626. He appears to have resigned upon being sent on a mission to Rome in 1629. In 1635 he appears once more as guardian of the Franciscan convent at Athlone, and in 1639 was provincial definitor of the Franciscans in Ireland. From 1641 to 1644 he served as provincial of the Irish Franciscans, a tenure that coincided with the outbreak of the October 1641 rebellion in Ireland. He established himself at Kilkenny, which became the capital of the newly formed Catholic Confederation of Ireland, and played a very active role in confederate politics.When he stepped down as provincial in 1644 he became guardian of the Franciscan convent at Kilkenny. A strong supporter of the confederacy, he called on Rome to excommunicate those Irish catholics who refused to join it, and he pressed the rights of the catholic church to confiscated monastic lands. In summer 1643, he may have gone to Oxford to represent the confederacy in negotiations with the king.
MacGeoghegan greatly impressed GianBattista Rinuccini (qv), papal nuncio to Ireland between 1645 and 1649, upon whose recommendation he was appointed bishop of Clonmacnoise on 11 March 1647 (N.S.), although he was not consecrated until 2 April 1648 at Waterford. He strongly supported Rinuccini's opposition to an alliance, favoured by many in the confederate assemblies, with the Irish royalists led by James Butler (qv), marquess of Ormond. As a result objections were raised to the presence of MacGeoghegan and other then unconsecrated bishops in the confederate assembly of autumn 1647, although he was eventually allowed to take his seat. In early 1648, as relations between Rinuccini and the supreme council of the confederation deteriorated, MacGeoghegan was one of an inner circle of five or six bishops to whom the nuncio turned for advice. He backed Rinuccini's May 1648 excommunication of those who adhered to the supreme council's truce with the protestant forces in Munster and accompanied the nuncio to Galway city that summer. Rinuccini's departure from Ireland in February 1649 marked the effective defeat of the nuncio's party after the supreme council had signed an alliance in January with Ormond, dissolving the confederacy in the process.
For most of 1649 MacGeoghegan concentrated on his duties as bishop and, on 10 May, held a diocesan synod at Clonmacnoise, which enacted a number of regulations for administering the diocese. By the middle of 1650 Cromwellian soldiers were sweeping across Ireland and Ormond had lost the confidence of most catholics. On 12 August 1650, MacGeoghegan and the rest of the catholic hierarchy met at Jamestown, Co. Leitrim, and excommunicated those who continued to obey Ormond as lord lieutenant of Ireland. Ormond agreed to resign in return for the non-publication of the excommunication. The Jamestown meeting also appointed MacGeoghegan to act as one of the six commissioners to further negotiations with Charles, duke of Lorraine, to act as protector of Ireland.
In autumn 1650, Ormond not having resigned, MacGeoghegan and other clergy attempted to publish the Jamestown excommunication, but Ormond forestalled this move by summoning a meeting of the catholic clergy at Loughreagh in November. Most of Rinuccini's supporters did not attend, though MacGeoghegan did. There he upheld the validity of Rinuccini's censures and refused to sign a letter of safe conduct for Ormond, who was now preparing to go into exile in catholic Europe. In April–May 1651 he attended another congregation of the catholic clergy at Galway city, which was again dominated by Ormondist clergy, headed by John Bourke (qv), archbishop of Tuam, who appears to have tried to sabotage negotiations with the duke of Lorraine. At MacGeoghegan's prompting Hugh O'Reilly (qv), archbishop of Armagh, held a provincial synod for Ulster at Cloghwater in July–August, which condemned Ormond and his supporters. This congregation then sent MacGeoghegan to Leinster where he succeeded in gaining a similar condemnation from a meeting of the clergy there.
Around the end of 1652 MacGeoghegan managed to escape from Ireland, and travelled to Spain, where he unsuccessfully petitioned the king to aid the Irish catholics. In autumn 1653 he went to Rome, where the college of Propaganda Fide gave him lodgings and a meagre allowance, which from 1655 was supplemented by a small Spanish pension. Perhaps as a gesture of reconciliation, in early 1655 he (unsuccessfully) petitioned the pope to grant a general absolution to those who had opposed Rinuccini in Ireland. However, by 1656, he was once more inveighing against Ormond, and that August he helped to secure the dismissal of the Ormondist Oliver Dease from his position as vicar general of Meath. This manoeuvre anticipated MacGeoghegan's transfer to the bishopric of Meath on 16 April 1657. He appears to have been ordered to return to Ireland, and in early 1658 he left Rome, arriving at Brussels in the spring. Much to the annoyance of his superiors in Rome, there he remained until the autumn. His reluctance to return to Ireland was understandable; it was still extremely dangerous for a catholic bishop to go back. However, he arrived in London on 12 May 1659, where he saw at first hand the death throes of the republican regime, before reaching Ireland and his new diocese later in the summer.
MacGeoghegan was the first bishop to return to Ireland since the Cromwellian conquest and he faced a daunting task. Forced to live in caves, he concentrated on imparting the rudiments of faith to the people and administered the sacrament of confirmation to large numbers. By September 1661 he had also ordained twenty-two priests. In October 1660 he and Edmund O'Reilly (qv), archbishop of Armagh, presided over a provincial synod of the Armagh clergy. However, O'Reilly's recall to Rome in April 1661 left MacGeoghegan once more with the burden of leading the catholic church in Ireland and at a time of severe crisis.
In January 1661 MacGeoghegan and O'Reilly had empowered Peter Walsh (qv), a Franciscan who enjoyed Ormond's favour, to congratulate the restored Charles II and to petition for toleration of catholicism. Walsh, however, supported the Remonstrance drawn up in London in December 1661 by Irish catholic landowners, which pledged loyalty to Charles in a manner that infringed the pope's authority and, with the government's backing, called on the Irish catholic clergy to sign it. The pope refrained from censuring the Remonstrance for fear that this would lead to renewed persecution in Ireland, but through less formal means had by late summer 1662 made it clear to his Irish flock that the document was unacceptable. Anticipating this in July 1662 MacGeoghegan and likeminded clergymen signed an instrument denying that they supported or had a hand in the Remonstrance. He also dispatched an agent to Louvain who on 29 December secured a condemnation of the Remonstrance from the theological faculty there. Thanks to MacGeoghegan's efforts, the overwhelming majority of the Irish clergy did not endorse the Remonstrance and the threat of a damaging schism was averted. He died in January–February 1664, probably at Cloonagh, Co. Westmeath, and was buried, at his own request, in the ancient cemetery of Clonmacnoise in King's County (Offaly).