Banagher was incorporated by a 1629 charter of 4 Chas I which granted to Sir Arthur Blundell his heirs and asssigns forever an area specified as 101 acres of arable and pasture and ten acres of bog and moor, in the town and lands of Bannacher-Srahnabrone, Locharrow, and Bealanaleek adjoining the river Shannon and further lands to a total of 200 acres of arable and pasture and 70 of wood and moor together with the liberty of fishing in the river Shannon. One-thirteenth of these lands were to be held by Sir Matthew Derenzie his heirs and assigns, and one-thirteenth by each of the other 12 burgesses named, at a like rent of 3s 1d. Provision was also made for a preaching minister to celebrate divine service in Banagher. The sovereign was to be a JP within the limits of the said corporation and also a coroner and clerk of the market. The corporation was entitled 'The Sovereign, Burgesses and Free Commons of the borough and town of Bannacher alias Bannagher',228 and the corporation at large was empowered to return two members to the Irish parliament.
The Banagher Borough Book 1693-1748 gives some interesting sidelights on the borough's affairs; for example, on 21 February 1694 Col. James Hamilton, an absentee, was removed by the common council because he was useless to them, and in 1705 Randall Knight, a burgess, was to be disfranchised unless he showed up at the next common council meeting. Elections for the sovereign were always unanimous, though not all burgesses were present, and between 1700 and 1727 the sovereign was almost invariably George or Peter Holmes (1031, 1032) or Hon. Charles Plunkett (1684). On 15 October 1715 the Hon. Charles Plunkett and Thomas Lestrange (1229) were unanimously elected MPs, and in 1727 the Hon. Charles Plunkett and George Holmes were similarly elected. After Charles Plunkett died in September 1729, William Sprigge (1975) was unanimously elected on 11 October 1729.
On 28 May 1734 Galbraith Holmes was elected MP in place of his father George Holmes, who died on 29 April 1734, by a majority of 25 to 14. Some seven months later he was declared not duly elected. There appears to have been a dispute in the borough which lasted for some years and upset the dominance of the Holmes family, as in 1735 Robert Holmes (5015) was elected MP in place of William Sprigge (1975),who died in August 1735, by a majority of 25 to 14, and then he was declared not duly elected. The two Holmeses were successfully challenged by Richard Trench (2109) and Henry Lestrange (1228). This was a reflection of a quarrel in the borough that lasted for about a dozen years, during which time Sir Laurence Parsons was elected a burgess in 1740 and sovereign in 1742. Parsons had married Mary, the daughter and co-heir of William Sprigge, in 1730, so he possibly felt that he had inherited Sprigge's interest in Banagher. The Holmeses were also connected with the Sprigges, as the not-duly-elected Robert Holmes' mother, and the aunt of Mary Parsons, was Lucy Sprigge.
The Holmes family gradually reasserted their control, and in 1775 it was thought that they had half the borough, but by 1783: 'The Patron Mr Holmes. Proprietor of the soil Mr Daly. But it is mostly let on leases for ever.' In 1785 Banagher was 'close'; 'Mr Holmes returns himself and sells the other return.' Five years later, in 1790, he had 'lately' sold his interest for £10,000 to Mr Alexander of Caledon (0029), and the commentator continued:
Mr Alexander's residence and principal property being in the County of Tyrone, the attention to the management of a Corporation at such a distance from him he deemed rather inconvenient and Mr Ponsonby being in precisely the same situtation with regard to his Borough of Newtown, in the County of Down, these two proprietors of the manufacturers of Members of Parliament made a mutual transfer of their respective stocks. In consequence of which Mr Ponsonby is now lord paramount of the Borough of Banagher and his word will nominate its future representatives.
This wholesale traffic of corporations has recently become so common and that too in Ireland, which has but just recovered its independence, as to excite neither murmur nor suprise, no more than if it were essential to the organisation of the constitution, instead of being, as it truly is, a destructive blemish on the eye of the political body.229
Prior to 1800 the corporation consisted of a sovereign, 12 burgesses and freemen all named by the patron and the form of election only was observed. Banagher was disfranchised by the 1800 Act of Union and the £15,000 compensation paid to Rt Hon. G. Ponsonby; since that year the corporate offices have not been filled.