Mac Lochlainn, Michael (Mauricius) (d. 1349), Franciscan friar and bishop of Derry (1319–49), may have come from the same family as Muirchertach Mac Lochlainn (qv), high-king of Ireland (1145–66), whose descendants had held the kingship of Cenél nEógain until 1241. He may also have had connections with their successors in that kingdom, a related family, the O'Neills, whose latest representative in the early fourteenth century was Domhnall O'Neill (qv). But little is known with certainty about his background and his date of birth is unknown.
Mac Lochlainn belonged to the Franciscan priory at Armagh, where he held the position of lector or 'reader', which implies that he had received a university education. Although there is no indication of where he studied, the university of Paris is likely since the General Constitutions of the Franciscans of 1260 made provision for two Irish members of the order to study there.
On about 31 August 1303 Mac Lochlainn was elected as archbishop of Armagh by the dean and chapter; the following October, Edward I gave royal assent and authorised him to go to Rome to seek confirmation of his election. However, Pope Benedict XI (d. 1304) refused to do so, on the grounds of his illegitimacy (he was allegedly the son of a nun). Mac Lochlainn was clearly a man of ambition who resented being passed over, and in 1310, presumably after petitioning the pope, was given permission by Benedict's successor Clement V (d. 1314), despite his illegitimacy, to seek any ecclesiastical office, including that of archbishop of Armagh. This he never achieved since the death of Nicholas Mac Maoil Íosa (qv) in 1303 had proved to be the end of the tenure of the see of Armagh in the medieval period by archbishops of native Irish birth.
In 1317 the document known as the Irish remonstrance, a powerfully worded indictment of English rule, inviting the pope to replace the English crown's lordship over Ireland with Edward Bruce (qv) of Scotland as king of Ireland, was sent to John XXII at Avignon. There is no indication in the document itself as to its author, other than the opening statement that it was sent on behalf of Domhnall O'Neill and the princes of Ireland. Nonetheless, there are some clues, at least to the kind of man who might have written the remonstrance. One is that the author's descriptions of the atrocities committed by the English secular lords in Ireland do not refer to any events after 1305, reserving the full power of his invective for the contemporary behaviour of the English clergy in Ireland: for Walter Jorz (qv), an English Dominican and archbishop of Armagh (1307–11); for the Cistercian monks of Abbeylara and of Inch, whom he accused of celebrating masses after attacking and slaying the Irish; and for a certain English Franciscan named Simon who allegedly claimed in the presence of Edward Bruce himself that it was no sin to kill an Irishman. This evidence, such as it is, suggests that the author of the remonstrance was a cleric, that he had a particular interest in the church of Armagh, and that he had a special hostility towards the English members of religious orders like the Cistercians and Franciscans. An analysis of the Latin text also shows considerable rhetorical skill and that the author made extensive use of the special metrical prose of the Roman curia.
Michael Mac Lochlainn was exactly the sort of person who could have composed the remonstrance: a cleric with an academic training, whose ambitions for high office had been disappointed. He also belonged to a religious order that was very deeply divided between its Irish and English members. Assuming that Mac Lochlainn really was the author of the remonstrance, which is plausible but probably unprovable, he was a man who was connected in very significant ways with both Irish political and ecclesiastical society at a very important phase of Irish history, the Bruce invasion. But Mac Lochlainn, if it were he, perhaps did more than just compose a document justifying the kingship of Edward Bruce for onward transmission to the pope. He may also have seen the Scottish invasion of Ireland as an opportunity to restore the independence of the church of Armagh within the framework of the restored high kingship in the hands of Edward Bruce, and preferably with himself as archbishop.
Mac Lochlainn finally gained preferment in 1319 when he became bishop of Derry. It is likely that he was closely related to Gofraid Mac Lochlainn, who had been bishop (1297–1315). Virtually nothing is known of his activities, except that in 1327 he and the chapter of Derry were in dispute with the heirs of Richard de Burgh (qv), earl of Ulster, over rights of patronage to certain churches, lands and rights belonging to the bishopric. In answer to Mac Lochlainn's petition to the pope, the archbishop of Armagh was ordered in February 1327 to resolve the matter. Michael Mac Lochlainn remained as bishop of Derry until his death sometime before 18 December 1349.