Innistiogue in the early part of the century appears to have been dominated by the Deanes: at least one member of the family (0599, 0600, 0601, 0604, 0605, 0610) sat continuously from 1692 until 1768. However, there was an ongoing dispute over the control of the borough between the Deanes and the Fowneses (0812). It is recorded that:
On one occasion the clan [Deaneites], having mustered in force is said to have marched towards Innistiogue from the direction of Graigue in full battle array and determined to carry the borough by storm. However, at that time, no goodly bridge spanned the Nore at this point, and the staunch supporters of Sir William Fownes having by a grand stroke of generalship removed all the boats to the Innistiogue side of the river, the followers of the rival Knight were stopped short in the midst of their career, and were obliged to content themselves with assailing the enemy by showers of stones across the water, after the fashion of Homer's heroes. The foe no less heroically returned the compliment; volley after volley of stones flew across Nore's classic stream, but as the combatants were unable to come to close quarters, their ammunition was expended without any serious results, and the patience of the Deaneites having at length become exhausted, they retired 'boatless home' and the doughty Burghers of Innistiogue, in the Fownes interest, remained masters of the day.214
Sir William undoubtedly strengthened his position when, in 1739, he married Elizabeth, the daughter of Brabazon Ponsonby. He appears to have further increased his hold on the borough about 1754 when 35 people were elected freemen; as residence was no longer required, they included many far-away freemen, for instance Shapland Carew of Waterford and James Smyth of Limerick. In 1755 a further 80 freemen were elected. The Deanes appear to have quarrelled among themselves, as in 1759 Joseph Deane Sr and Joseph Deane Jr stood against each other for portreeve, which Deane Jr won by a large majority. Then from 1761 to 1769 Sir William Fownes was portreeve, and this probably marks his final triumph. There may also have been a financial element in Fownes' triumph, as in 1756 he complained that 'Ned Deane' (0601) had promised to give Fownes the borough and Fownes had maintained his family and him for a long time. Then Deane had allowed himself to be arrested for debt and refused to vote for Fownes unless paid £800.215
On Sir William's death in 1778 the borough was inherited by his heiress daughter, Sarah, who had married William Tighe (2072); their son, William (2073), received the £15,000 compensation for the disfranchisement of the borough at the Union.