Carlow75 was a very old corporation incorporated by Edward I in 1296 and it had two seventeenth-century charters: one granted by James I in 1613 granted the provost and burgesses the right to return two MPs. There was also a charter granted by James II in 1689. The corporation was to consist of a portreeve, burgesses and commonalty. A further charter granted by Charles II in 1674 defined the corporation as consisting of a sovereign, 12 free burgesses and commonalty. Excluding Dublin, it was the fourth largest town in Leinster with a considerable proportion of protestants in its population, including Huguenots. Like many parliamentary boroughs, its practice was uncertain between 1692 and 1715 and most elections during this period were disputed. The principal issue was whether freemen, resident or non-resident, were eligible to vote. In 1703 there was a double return. The Returning Officer made out the writ for Richard Wolseley (2246), the Hon. Charles Howard (5016) and Walter Weldon (2202). The Committee on Privileges and Elections presided over by Sir Richard Levinge (1230), appearing to rely solely on the charter of Charles II, declared it to be a new borough and that it had two types of freemen, those resident who paid a tax known as scott and lott and those non-resident who did not. The committee agreed the return of Richard Wolseley (whose family represented the borough with a short break in 1724-7 until 1768) but a question arose over Weldon and Howard and the status of their voters. Weldon had 46 votes and Howard 61, but while Weldon's votes were by resident tax-paying voters, Howard's were mainly non-resident and non-taxpayers. Howard's interest derived from the Earl of Suffolk (whose son had married a daughter of the Earl of Thomond). Both had six burgesses but Howard's included the Sovereign, whom Weldon said should not have a vote and Howard declared should have two votes. The committee made a full report76 to the House and decided for Weldon; the House endorsed this decision.
In 1712 Benjamin Burton (0292), the Dublin banker, purchased, along with other lands in the county, from the Commissioners for Sale of Forfeited Estates a considerable estate in the barony of Rathrilly about 15 miles from Carlow town. Burton's partner, Francis Harrison (0973), also had lands in the vicinity. Despite the spectacular failure of Burton's Bank in 1733 and the subsequent sale of the contents of Burton Hall, the Burtons appear to have managed to hold on to the estate itself and in the course of the century to have acquired absolute control over the corporation of Carlow. The freeholders appear to have vanished, and the borough became a closed and saleable commodity. In 1795 William Henry Burton sold it to Charles Bury (0305), Lord Charleville, for £13,000. It survived the Union and returned one MP to the Westminster parliament; the franchise remained unchanged until 1832.