Browne, ‘the great Leviathan of Mayo’, entered the Irish parliament for that county in 1782 on the interest of his elder brother, Lord Altamont. He prided himself on his support of Pitt’s administration, and during the struggle for the Union, which he strongly favoured, asked Pitt for an Irish marquessate for his brother, who duly became Marquess of Sligo on the eve of the Union.
Browne evidently attended, and having eliminated one of his opponents in a duel was returned unopposed at the general election of 1802, but emerged disgruntled at his new colleague Dillon’s being ‘friendly to opposition’, while his brother was disappointed at not obtaining a British peerage.
Browne went on to support Pitt’s second ministry, replying in debate to opposition allegations of military rule in Ireland, 15 June 1804. On 7 June he had described himself as a friend to the abolition of the slave trade, but asked for more information before voting for it. On 8 Feb. 1805 he justified the suspension of civil liberty in Ireland by reference to French provocation there. In April, assizes and recruiting duties detained him in Mayo and, although he came over in time for the debate on the Catholic petition, a judicious illness kept him away from the division.
Browne could be counted on to support the Portland ministry after his return to England in mid-April 1807, leaving Mayo restored to ‘quiet’.
Wellesley, who regarded Browne as the more ‘reasonable’ of the two brothers, noted of him that year: ‘supports government, is a cordial friend and attends constantly. Has no particular object, but his brother Lord Sligo urges requests occasionally.’ Browne had a difficulty about the Catholic question, as he informed Wellesley, for his family had been supported for 50 years by the Catholic interest in Mayo and he had since the 1790s felt obliged to favour their claims. While he had been able to prevent a Catholic petition from Mayo, he wished to vote for them on 25 May 1808, as even an abstention ‘will ruin my influence which you may want on critical occasions’. With the chief secretary’s leave, he duly voted pro-Catholic.
Browne supported Perceval’s ministry throughout the Scheldt inquiry debates, January-March 1810, and was dismayed at their weakness, as well as at his own exclusion by vote of the House, 31 Jan., from the finance committee: to him it demonstrated Bankes’s mastery over government and the reduction of the influence of the crown in the face of the rage for economy and democracy, not only out of doors, but also in the House. Thereafter he seems to have lost interest. The death of his brother the previous year had deprived him of a ‘prop’ and by November he was excusing himself from leaving Ireland to show what the viceroy described to him as his ‘zeal and attachment to his Majesty and ... regard for the present administration’. He missed the Regency debates and, it would seem, much of the rest of that Parliament, though he assured Perceval, hailing him as a worthy successor to Pitt, 7 June 1811, that ‘my attachment to you will not lessen with your loss of power’. Browne managed to irritate the viceroy in March 1812 by sponsoring a pro-Catholic petition which, while intended to counter the activities of the Catholic committee, was strongly in favour of emancipation. The chief secretary, however, pointed out that, in Catholic counties, no man had ‘either nerves or sense sufficient to resist the Papists’.
Browne was satisfied with the Castle’s recognition of his family’s exclusive right to patronage in his ‘kingdom of Mayo’ since 1783 and believed chief secretaries Wellesley and Wellesley Pole to have confirmed it and only the Grenville ministry, whom he disliked, to have resisted it. He was dismayed when he met with resistance to these pretensions from the chief secretary, Peel, whom he treated in January and February 1813 to both written and oral explanations of his expectation of a monopoly in Mayo in return for his long record of disinterested support. He did nothing to conciliate Peel when he announced on the eve of the Catholic debate, 2 Mar. 1813, ‘that he should vote and speak perhaps for the committee, but that he should be very sorry if we went into it’. Peel’s comment was: ‘By such votes is Ireland to [be] kept in a ferment’.
Browne again fell foul of the chief secretary, who no longer had any patience with his long-winded complaints, on his failure to secure a barrack mastership in Mayo, March 1815. He denied Peel’s allegation that such an appointment was outside county patronage—as well as the insinuation that it was a job to please Lord Dillon, whose agent Browne had nominated. (It was about this time that Browne was reported to be coming over from Ireland in high dudgeon at George Rose’s proposal to repeal the import duty on foreign linens, threatening to impeach Rose, and adding that he would ‘give half of his estate in Mayo to see [Rose] hanged in a rope made from foreign flax seed’.)
In an embittered valedictory letter to the chief secretary, 5 June 1818, Browne, while admitting his ‘inability to assist in debate’, complained of government’s neglect of his own services and of the interests of his sons, ‘better educated than was their father’. In fact, though Browne retired at the dissolution, two of his sons, James and Peter, came into Parliament, the former succeeding him as county Member, and he rejoined them as Member for Kilkenny on his kinsman Lord Desart’s interest in 1820. All three supported the government, which still found it impossible to satisfy Browne’s appetite and, on his retirement in 1826, did not grant his son’s request for a peerage for him. He died 14 Aug. 1828, ‘aged 68’.