Lord Castelreagh was the 2nd. Marquess of Londonderry. In Ireland, as the architect of The Act Union of 1800, he became a controversial political figures. But had more support as Foreign Secretary in Lord Liverpool's government where he masterminded the coalition against Napoleon and the Congress of Vienna of 1815.
William Carr Beresford was the illegitimate son of the 1st. Marquess of Waterford but was elevated to the peerage, firstly as Baron Beresford in 1814, then as Viscount Beresford in 1823. He served with distinction under Wellington in the Peninsular Wars, was M.P. for County Waterford and became the Governor of Cork.