Baron (Barron), Bartholomew (Bonaventure) (1610–96), Franciscan theologian and miscellaneous writer, was born 24 July 1610 at Clonmel, Co. Tipperary, the second son of Lawrence Baron (d. 1622), a merchant of Clonmel, and his first wife, Maria (d. 1616), sister of Luke Wadding (qv), the founder of the Irish Franciscan college at Rome, St Isidore's. His parents died when he was young, but his elder brother, Geoffrey Barron (qv), ensured that he was well educated. He learned rhetoric at Clonmel, studied briefly at Waterford, and then entered the Franciscan novitiate at Timoleague, Co. Cork, in summer 1626. He joined the Franciscan order there on 27 October 1626.
Around March 1629 he left Ireland and for several years studied philosophy on the continent, at Louvain, Salzburg, and Augsburg. Between 1631 and 1633 he travelled in Europe before settling down to resume his studies; he arrived at Rome on 8 January 1633 and embarked on the study of theology at St Isidore's College. He was ordained on 3 September 1634, taking the religious name Bonaventure. He was appointed a lecturer in St Isidore's on 4 September 1635, later becoming a professor of theology and establishing himself as a distinguished academic and renowned man of letters. A prolific writer, he published a large number of works on theology, philosophy, science, and history, as well as collections of poetry. He was famed in Rome for the beauty of his Latin, both prose and verse, and believed strongly that writers needed both knowledge and the ability to express that knowledge elegantly. Despite his post as lecturer in theology, he appears to have disliked that discipline and was happiest when composing poetry; indeed, in 1651 he voiced a fear that his lecturing in theology was having a detrimental effect on his writing style. Many of his essays, poems, epigrams, and epistles written during the 1630s and 1640s are engagingly personal and are of greater interest to the modern reader than his rather dry scholarly works.
In 1668 Baron was offered the archbishopric of Cashel, but he declined the post and never returned to Ireland. However, he followed events there with interest, being a strong opponent of English rule in his native country. In one of his histories he refused to recognise Queen Elizabeth I as the rightful ruler of Ireland. In 1642 he went to Rochelle, from where General Thomas Preston (qv) and his Irish force were setting sail for Ireland to fight for the Catholic Confederation. Geoffrey Barron served in the Leinster army of the confederation and Bartholomew published his diary of the siege of Duncannon, Co. Waterford, in 1644–5. Geoffrey enjoyed a distinguished career within the Catholic Confederation as a statesman, soldier, and diplomat until his execution by the Cromwellians at Limerick in 1651. In that year Bartholomew referred somewhat guiltily to his comfortable life in academia.
In 1653 he appears as the custos of the Franciscan province of Scotland, a titular appointment; it is unlikely that he was in Scotland. He briefly left Rome in 1656 to be commissary to the province of Bosnia-Croatia. During the 1660s and 1670s he travelled widely, lecturing and writing; his movements are not clear, but he spent 1661–3 in Austria and Germany (he is known to have visited Würzburg, then Paris), and in 1669 became a lecturer in humanities at St Bonaventure's friary at Lyons, France. In 1672 he was in Milan, and around 1674 he went to Florence, where he resided at the friary of San Francesco al Monte and on 15 September 1676 became historiographer and theologian to Cosimo III, grand duke of Tuscany; Cardinal Ludovisi is known to have tried to remove Baron from Florence to prevent him from publishing his writings. However, Baron began to prepare an edition of all his published works, which he planned to issue in a twenty-two volume edition, and he engaged two Franciscans to seek out copies of his works in the many cities where they had been published.
Probably around 1678–9, and at the very latest by March 1683, Baron returned to his post as lecturer in theology at St Isidore's, but his sight began to fail and he retired in 1686; during his final years he suffered from paralysis and total blindness. He died on 18 March 1696 and was buried at St Isidore's. There are four surviving portraits of him: two in oils are at the Franciscan houses at Clonmel and Merchants’ Quay, Dublin; the third is a copperplate engraving prefixed to some of his works. The fourth is a fresco in the aula of St Isidore's College, Rome. Late in life he wrote an autobiography, which was lost at the end of the nineteenth century.