Bermingham, John (d. 1329), earl of Louth and justiciar of Ireland, was eldest son of Peter Bermingham (qv), lord of Tethmoy, and Ela, daughter of William de Oddingeseles, justiciar of Ireland 1294–5. After his father's death his marriage was granted to Richard de Burgh (qv), the earl of Ulster, on 10 June 1308. By 1310 he had closely attached himself to his father's old ally, John fitz Thomas FitzGerald (qv), and was involved in a bloody dispute with the de Lacys of Meath. In 1313 they were together again, warring against the Irish of Offaly. For the next two years he was in receipt of large sums from the Irish exchequer to maintain war against the O'Connors and to pacify the marches of Kildare.
His rise to prominence was due to the patronage of Roger Mortimer (qv), lord of Wigmore and Trim, who knighted him in 1317. In June and July 1315 he was part of an unsuccessful expedition raised to oppose the invasion of Ireland by Edward Bruce (qv), and in January 1316 was present at the battle of Skerries. Appointed by Mortimer as captain of the Anglo-Irish forces of Louth and Meath who were victorious at the battle of Faughart on 14 October 1318, he set out for England to deliver the head of the Scottish leader to Edward II. As a reward for his success he was created earl of Louth at a parliament held at York on 12 May 1319, and was granted the county to hold as a liberty.
Shortly afterwards till 3 February 1320, he was one of those commissioned to inquire into the vexed issue of those Anglo-Irish who had supported Bruce. On 7 June 1319 he was accorded wide-ranging powers to grant English law to all of his Irish tenants. While in England on 21 May 1321 he was entrusted with the justiciarship of Ireland, and (sensing the changing political climate) abandoned his old mentor, Mortimer, and sealed an indenture with the younger Despenser (28 May). Subsequently, according to his own testimony, he was attacked by Roger Damory and forced to flee to Normandy and from there make his way back to Ireland in August.
His period in office coincided with a rise in his family's fortunes, particularly that of his brother William (qv). His first task was to lead an assault on Mortimer's adherents and lands in Ireland, and in December 1321 he was empowered to investigate all judicial matters that had come before the lord of Trim, and purge any partial personnel from the administration. In April 1322 he was summoned as head of a large contingent to Scotland, but he arrived (August) to witness the deterioration of the English war effort. The following year he led an army against the Irish of Ely O'Carrol. Removed from his post, probably at his own request, in November 1323, he continued to act as justiciar till the arrival of John Darcy (qv) in February 1324.
He then began to concentrate on the affairs of the earldom, though he was summoned to parliament in Dublin in the same year. He was closely involved in the disputes that broke out between the great Anglo-Irish lineages in 1327, coinciding with the return to power of Mortimer in England. According to a highly dubious enquiry in 1332 into the treason charges brought against the earl of Desmond (qv) (Maurice fitz Thomas FitzGerald), Bermingham, his brother William, and a number of others formed a confederation at Kilkenny in July 1326, or more likely 1327, to make Maurice king of Ireland. In February 1328, at a compurgation at Kilkenny, witnessed by Bishop Ledrede (qv), he supposedly bound himself formally to fitz Thomas. As Mortimer slowly imposed order on Ireland, the only contact between the regime and Bermingham took the form of reprimands, though he was present at parliament in Dublin on 2 April 1329.
On 10 June he was murdered (along with two of his brothers and a large number of retainers) at Braganstown, near Ardee, by the gentry of Co. Louth, who were pursuing a number of his Irish kern for indiscriminately burning their manors. An obituary in the Annals of Connacht describes him as ‘the most active and vigorous, generous, and bountiful baron of Ireland [who] was treacherously slain by his own people’. His assassination occurred as a result of the friction caused by Edward II's creation of the earldom for him. In 1319 he held no territory in Louth and had no links with its leading families. Despite indictments brought against his murderers, they put their case to the English government and on 2 September 1329 they received a pardon from the Mortimer regime. His widow was left to pursue justice alone, ultimately in vain.
He married Avelina, daughter of Richard de Burgh; they had three daughters. His earldom lapsed, and the liberty of Louth, though granted in tail male, was appropriated by Mortimer after his death.