Leverous, Thomas (1485×1490–1577), catholic bishop of Kildare, was probably born in Co. Kildare during the late 1480s. In 1540 he was described as being at least 50, while his role as foster-brother to the future 9th earl of Kildare, Gerald Fitzgerald (qv) (d. 1534), suggests he was born c.1487, which was Fitzgerald's year of birth. Nothing is known of his parents. After becoming a priest, he was appointed vicar of Laraghbrine and Keroghe in the parish of Maynooth and became a member of the household of the Fitzgerald earls of Kildare, probably acting as tutor to the children of the 9th earl. In 1534 the Fitzgeralds of Kildare rebelled against the crown, but they had been defeated by August 1535. The government immediately set about arresting the leading members of the Kildare dynasty, but temporarily overlooked the 9th earl's eldest son from his second marriage, Gerald Fitzgerald (qv). Leverous was then tutor to the 10-year-old Gerald and in February 1536 fled with him from the castle of Donore, Co. Kildare.
The fugitives hurried through the midlands, receiving sanctuary from a number of Geraldine sympathisers before spending several months under the protection of Conchobhar O'Brien (qv), lord of Thomond. Then O'Brien sent him and Leverous to Co. Cork, where they were protected by Gerald's aunt Eleanor MacCarthy in Kilbritton castle. The province of Munster was not under the crown's jurisdiction, but the government put considerable diplomatic pressure on the lords there to surrender Gerald, who succeeded to the suppressed earldom of Kildare following the execution of his half-brother Thomas Fitzgerald (qv), 10th earl of Kildare, in February 1537. Thus, in summer 1538 Eleanor bought Leverous and his ward north to Tyrconell, where she married Manus O'Donnell (qv). In spring 1539 a nationwide rebel confederacy known as the Geraldine League was formed with the intention of restoring Gerald as earl of Kildare and defending the catholic faith. Writing in 1577, Richard Stanihurst (qv) claimed that Leverous played an instrumental role in its formation, but this seems unlikely.
By the close of 1539 the Geraldine League had all but collapsed due to a series of military reverses, necessitating the flight by ship of Leverous and Gerald from Tyrconnell to France in late February and early March 1540. They landed at Morlaix, Brittany, where they remained for four days or so. Alarmed by the interest expressed in Gerald by a number of English merchants in the port, Leverous kept him on the move. They took ship for Saint-Malo, which they reached on Palm Sunday 1540. From May 1540 to February 1541 they resided at the royal court in Paris before proceeding to Brussels, where the emperor Charles V granted Gerald an annual allowance and allowed him and his entourage to reside in the palace of the bishop of Liège. Fear of Gerald's kidnapping by English agents led his party to leave Liège after six months. In any case it was obvious that neither the French nor Charles V were prepared to offer military assistance to the Fitzgerald cause.
Ever since coming to France, Leverous had been in contact with the exiled English cardinal Reginald Pole, who encouraged him to bring his young charge to Rome. After their arrival there (late 1541) Gerald was granted papal protection, while Leverous became a member of Pole's household. Although he remained close to Gerald, he no longer acted as his tutor and guardian. With Pole's support, he was permitted to join the English college of St Thomas in Rome. It is likely that this period in Rome strengthened his catholic convictions, although little is known of his views prior to his exile. Following the death of King Henry VIII (1547), the succeeding regime of Edward VI decided to pardon Gerald in order to prevent his becoming the focus of foreign and rebel Irish intrigue. In June 1549 Leverous accompanied Gerald to London before continuing alone to Ireland, receiving a royal pardon for his past opposition to the crown in October.
He resumed his work as a priest to such good effect that in 1551 the lord deputy of Ireland, Sir James Croft (qv), commended his preaching, learning, and virtuousness, and advised that he be appointed a bishop. At this time the Church of Ireland was desperately short of qualified and Irish-speaking clergy, which may have induced Croft to overlook Leverous's catholic sympathies. The mooted promotion to the episcopate did not occur, probably because Leverous was opposed to the unambiguously protestant nature of the Church of Ireland at that time.
The accession of Queen Mary (1553) led to the full restoration of catholicism as the state religion and to the appointment of Leverous's former patron Pole as papal legate to London. The Irish clergy overwhelmingly favoured catholicism, but many had been tarnished by their willingness to countenance the protestant innovations, which led Pole to place a premium on reliably catholic clergy. Along with George Dowdall (qv) and William Walsh (qv), both of whom had also served Pole in Rome, Leverous was to spearhead the renewal of the catholic faith in Ireland under Pole's direction. In June 1554 all three were appointed to a royal commission authorised to deprive married clergymen of church office. This proved an effective means of purging the church in Ireland of committed protestants, and took up much of his time over the following years. One of the victims of this process was Bishop Thomas Lancaster (qv) of Kildare, and Leverous was appointed by the queen to this vacant diocese on 1 March 1555, receiving his papal provision on 30 August 1555. On 25 March 1555 the queen restored the dissolved cathedral chapter of St Patrick in Dublin and appointed him dean of this institution. In 1556 his former student Gerald Fitzgerald returned to Ireland, having been acknowledged by the crown as 11th earl of Kildare and restored to much of his family's lands. Leverous acted as one of his chief counsellors and presumably cooperated closely with him in the local administration of Co. Kildare. About the start of 1558, he became a member of the Irish privy council, but seems to have concentrated mainly on his ecclesiastical duties.
The accession of the protestant Queen Elizabeth I in late 1558 threatened his position, and the royal authorities quickly identified him as a potential leader of catholic resistance to the reintroduction of the reformation church settlement in Ireland. True to form, in January–February 1560 he opposed in the Irish parliament the crown's legislation reestablishing royal supremacy over the church, but was not seconded by the bulk of his episcopal colleagues, who had no desire to jeopardise their positions. On 4 February he refused to take the oath of supremacy, which he justified by arguing that as women were not fit to exercise any form of ecclesiastical authority, he could not recognise Elizabeth as head of the Irish church. In fact, his true objection was not against Elizabeth's gender but against her religion. This sophistry availed him little, as he was deposed as bishop of Kildare and as dean of St Patrick's.
He remained in Kildare for a time, where he preached in opposition to the Church of Ireland, much to the annoyance of the protestant authorities, who pressed the earl of Kildare to take action against his former mentor. Kildare arranged for him to receive employment as master of Adare grammar school in Co. Limerick. Owing to the government's lack of influence over this part of Ireland, his religious views proved less controversial there. During this time he enjoyed the patronage of Gerald Fitzgerald (qv), 15th earl of Desmond, and moved from Adare to a grammar school in Limerick, where he was assisted by Richard Creagh (qv). The papacy considered appointing him archbishop of Armagh in recognition of his loyalty but was dissuaded by his age and advanced Creagh to this position instead. About 1564–5 Leverous returned to Kildare, where he continued to preach and administer the sacraments, although his infirmities increasingly restricted his activities. In February 1569 his signature appears on a petition to the king of Spain on behalf of the catholics of Ireland, appealing for military aid to overthrow the heretical government of Elizabeth. However, other signatures on this document are forged, so it is uncertain whether his was genuine. He died in October 1577 at Naas, where he was buried in the church of St David's.