Barry, John Maxwell- (1767–1838), MP, soldier, and 5th Baron Farnham , was born 18 January 1767 in Dublin, eldest of two sons of Henry Maxwell (d. 1798) – bishop of Dromore (1765–6) and Meath (1766–98), and third son of John Maxwell (d. 1759), 1st Baron Farnham, of Farnham, Co. Cavan – and Margaret Maxwell (d. 1798), only daughter of Anthony Foster of Collon, Co. Louth, and sister of John Foster (qv), last speaker of the Irish house of commons. He was admitted to TCD in October 1783. Elected MP for Co. Cavan (1787) through family influence, he was unseated by petition the following year. A tory and a firm protestant, he was MP in the Irish parliament for Doneraile, Co. Cork (1792–7), Limavady, Co. Londonderry (1798–1800), and in the UK parliament for Co. Cavan (1806–23). He was also sheriff of Co. Carlow (1796) and colonel of the Cavan militia (1797–1838). He was in Wexford when rebellion broke out there (27 May 1798) and assumed control of the Wexford town garrison. Although fellow officers argued that their position was indefensible against the large rebel army, he held out against abandoning the town. However, after he had led an unsuccessful sortie against the rebels on Forth Mountain, the discipline of his troops crumbled and he reluctantly retreated to Duncannon fort (30 May 1798). In June he was elected to a commons secret committee to investigate the rebellion. He proposed in the commons that martial law should be applied retrospectively to imprisoned United Irishmen and that they should be summarily tried and executed, a proposal that received considerable support. In October 1800 he succeeded to the estates of his great-grandfather, James Barry of Newtownbarry, Co. Wexford, and took his surname; it was as ‘Colonel Barry’ that he became a well known MP. Under the influence of his uncle and mentor John Foster, he opposed the act of union, and was one of the opposition's chief critics of the union's commercial proposals.
He stood unsuccessfully for Co. Cavan in 1800 (but was elected in 1806) and became private secretary to Foster (1804) when Foster was made chancellor of the Irish exchequer. At Westminster he consistently opposed catholic relief and the reform of sinecures, grand juries, and parliament. He was commissioner of the Irish treasury (1807–17), and on its amalgamation with the British treasury was appointed a lord of the treasury (1817–23). He was also governor of Co. Cavan (1805) and a trustee of the Irish linen board (1810); for supporting the Portland ministry (1807–9) he was appointed to the Irish privy council (1809). In 1812 the viceroy dismissed his application for the post of chancellor of the Irish exchequer on the grounds that he was too lazy. In fact, he had little enthusiasm for his treasury position and was criticised by the chief secretary (April 1815) for visiting the Continent and neglecting his parliamentary duties. In 1823 he succeeded his cousin John James Maxwell (1759–1823), 4th Baron Farnham and MP for Co. Cavan (1780–83, 1793–1800), as Baron Farnham, becoming one of the largest landlords in Cavan and a representative peer for Ireland. In the house of lords he played an important role in liberating the Irish representative peerage from government nomination. An enthusiastic patron of evangelical missionaries on his Cavan estates, he helped set up an Association for Promoting the Second Reformation c.1826. He died in Paris 20 September 1838, was buried at Newtownbarry, and was succeeded by his brother Henry Maxwell, who died 19 October 1838.
He married (4 July 1789) Juliana Lucy (d. 1833), daughter of Arthur Annesley (1744–1816), 1st earl of Mountnorris; they had no children.