 The village which developed around the mainland pier which served Rutland, Burtonport, still bears his name.In 1785 Conyngham commenced the building of Slane Castle, assisted by his nephew the 1st Marquess Conyngham, on a site overlooking the River Boyne just a few kilometres upstream from the site of the Battle of the Boyne.From 1793 Conyngham was one of the Commissioners of the Treasury for Ireland.