The twins, John (The Master) and William, were born in the house in Merrion Square in 1814. Robert had married Lady Emily Le Poer Trench, daughter of the Earl of Clancarty, and there were four children of this marriage. Robert La Touche, took over at Harristown. John died in 1805 and his son, John, succeeded. Of these five Lecky declared: 'this family may claim, what is in truth the highest honour of which an Irish family can boast - that during many successive Governments, and in a period of the more lavish corruption, it possessed great parliamentary influence, and yet passed through political life untitled and unstained.' In spite of this setback, John sat as a knight of the Shire and was one of the five La Touches (the Five Just Men) who sat in the last House of Commons at the time of the Union. John lost, and the merchants of Dublin were so disappointed that they presented him with a gold snuffbox. In 1767, John tried to get elected to Parliament as Member for the City of Dublin, his opponent being the Marquis of Kildare, (later Duke of Leinster).

John enclosed the present demesne and built a new road and bridge over the Liffey. In 1768, David (The Second) La Touche bought Harristown, but it was David's son, John, who was the first La Touche to take up residence. When Sir Maurice died in 1704 the estate was inherited by his three daughters and divided into three parts - Harristown, Mullacash and Carnalway. The estate rose to prominence under Sir Maurice Eustace, who built the present house in 1662, became Lord Chancellor and obtained a charter from Charles the Second in 168 1, constituting his estates a manor. The historic lands of Harristown Demesne were in the hands of the Eustace family since the 16th century.

La touche family history