Brown, Ignatius (1630–79), Jesuit, was born on either 1 or 9 November 1630 in Co. Waterford, and by the late 1640s he was studying philosophy at Compostella in Spain. On 27 June 1651 he entered the Society of Jesus as a novice at Villagarcia before resuming his studies, this time in theology, at Valladolid. Following his ordination c.1658, he remained in Valladolid, where he taught philosophy for a period.
In spring 1663 he travelled to Ireland in the company of another Jesuit, Andrew Sall (qv), to join the Jesuit mission in his native land. From his base in Waterford, he toured south Munster, ministering to the faithful. Although he was arrested in 1668, an Irish noble quickly arranged his release. On 15 August of the same year he pronounced his final vows. In 1671 he was transferred to Drogheda, and was appointed superior of the Jesuit house in Dublin two years later. However, he never took up this position, due to poor health, and withdrew to the Continent via England.
By autumn 1673 he was in Paris, where he played a role in efforts to establish a foundation for the Irish Jesuits in France. Royal permission to establish such a house in the Jesuit province of Aquitaine was duly granted in April 1674, after which Brown purchased a building in Poitiers. He and his Irish colleagues hoped that the foundation would function as a seminary, but the Jesuit general refused to permit this. Instead it was to provide an education for young lay Irish catholics and to act as a refuge or place of retirement for Jesuits on the Irish mission. He did not obtain actual possession of the house till winter 1675–6, and was formally appointed rector of the Irish college at Poitiers in April 1676. In 1677 the college was described as having many boarders. The college was expected to be funded by donations from Irish catholics, but the actual sources of its endowments are uncertain and aroused the suspicion of Brown's superiors. It appears that the college was mainly funded by largesse from the Portuguese queen of England, Catherine of Braganza.
Meanwhile, his former colleague and travelling companion Sall had created a sensation in Ireland by converting to protestantism in 1674, a decision that he sought to justify in a sermon preached at Christ Church cathedral, in which he outlined a number of what he saw as false doctrines upheld by the catholic church, placing particular emphasis on its claim of infallibility. In 1675 Brown published his The unerring and unerrable church, in which he vigorously upheld this claim, arguing that scripture required an infallible authority to interpret it. Sall's apostasy had attracted a plethora of catholic denunciations, but it is a testament to Brown's skill as a controversialist that Sall devoted the bulk of his True catholic and apostolic faith (1676) to refuting his criticisms. Brown wrote under a pseudonym, leaving Sall unaware of the identity of his bitterest critic. Brown unleashed a final salvo against Sall with his An unerrable church or none (1678).
In early 1679 he resigned as rector of the Irish college and went to Castile to serve as confessor to the niece of King Louis XIV of France, Marie Louise, who had just married King Charles II of Spain. He died 30 December 1679 at Valladolid. He appears to have been the author of a pamphlet entitled Pax vobis. Purporting to be a dialogue between two English protestants, this was a theological satire directed against the protestant religion. Published in 1679, it went through six editions in the ensuing decade and was popular among English catholics.