William O'Shaughnessy

Upon his father's death in July 1690 following the Battle of the Boyne, he became The Ó Seachnasaigh, but because of the defeat of his side in the Williamite War in Ireland, his ancestral property was forfeited and he was never able to return home.

O'Shaughnessy served in the armies of France in the hope that Irish support would enable James II, or his successors, regain the throne of Britain and Ireland.

The Regiment performed a similar task two years later at the Battle of Ramillies, preventing the Dutch and English from completely wiping out the army.

Major-General O'Shaughnessy was of the Uí Fiachrach Aidhne dynasty, making him a direct descendant of Fiachrae mac Eochaid Mugmedon (fl.

(1736–1748) of Ossory, who died in 1748, tried in vain for decades to recover their lands from Sir Thomas Prendergast and his heirs, but without success.

The register of death of the church of Saint Willibrord, Gravelines, states that: On 2 January 1744, there died in the communion of our mother church, having had the holy sacraments administered to him Missire Guillaume O Shaughnussy, knight of the order of St. Louis, lieutenant-colonel of the Irish regiment of Clare, marechal de camps et armess of the king, employed at Gravelines in the service of his majesty; he was a native of Gort-inchygory, county Galway, province of Conought in Ireland, aged seventy years, married to Dame Maire Jacqueline Gauville.

He was inhumed in the chancel of the church by me, cure and dean, on the fourth of this month, in the present of John Baptist de Lalande, brigadier of the king's armies and the king's lieutenant at Gravelines, Monsieur Thomas Maguire, captain of the regiment of Clare, and of James O Shaughnussy, cadet in the defunct's company and his relative;