For most of the 18th century the 1st Marquess of Hertford was patron of this potwalloping borough, of which his descendants were described as owners in fee simple. Hertford usually managed to settle his electoral affairs in Ireland with a minimum of difficulty. The only serious set-back he had suffered had been at the general election of 1783, when the two volunteer candidates defeated his nominees.2 After the Union, Lisburn elections returned to normal, although the 2nd Marquess, who had succeeded in 1794, never forgot the defeat the family had suffered.

After having returned members of his own family circle for four successive general elections, Hertford was persuaded by government to bring in John Leslie Foster in 1818. Within a week of this bargain being struck in London, Foster, an able lawyer and a keen anti-Catholic, was offered the seat for Armagh city by the archbishop. Peel was naturally eager to obtain both seats for government supporters and proposed that Foster should be returned for both, vacating Lisburn at the beginning of the new parliamentary session. The following day he changed his mind and requested that a personal friend, John Wilson Croker* should come in for Lisburn, instead of Foster. Unbeknown to either Peel or his London colleagues, Hertford, who was ‘old in mind and body’ and in at least one opinion ‘unmanageable’, had been sending daily letters to his Lisburn agent to supervise Foster’s return, on the grounds that his influence in the borough was not as powerful as it once had been. Furthermore, Foster had been conducting a personal canvass there and had reported to government that Hertford ‘in his present state of health and anxiety about the borough’, would be almost ‘killed’ by the prospect of having to secure the return of a candidate other than himself. In the event, government chose not to risk Hertford’s spleen and Foster remained the candidate for both Lisburn and Armagh.

At his election the 75 protestant electors did Foster proud. He commented:

The protestant feeling of Lisburn converted the ceremony of chairing into a greater pageant than was perhaps desirable, but which it was impossible to avoid. I am informed that there are not above 20 Catholics out of a population of 7,000 in the town. A chair, a canopy of orange silk, military music, protestant favours, and a procession of several thousand persons were all prepared, I could not find out by whom, and carried me in due state until they and I were more than satisfied with the amusement.3

At the beginning of the new session, Foster duly vacated Lisburn to sit for Armagh, and Hertford, presumably as a result of the muddle that had resulted from his dealings with government, returned a member of his family at the by-election.