On his death at the Battle of Malplaquet he was succeeded by his son Sir Thomas Prendergast, 2nd Baronet. His widow was greatly troubled in her later years by protracted lawsuits against the Butler family of Ballyline over the right to certain lands in County Galway, and several other lawsuits, including one involving her own brother. Jonathan Swift, a bitter personal enemy of the younger Thomas, extended his hatred to the elder: "him who shamed our isle, traitor, assassin and informer vile". This appears to be a garbled reference to the Assassination Plot.