William Ponsonby, 1st Viscount Duncannon Irish politician (1659–1724) Parents Elizabeth Folliott Sir John Ponsonby Children Dorothy Ponsonby Henry Ponsonby Mary Ponsonby Elizabeth Ponsonby Brabazon Ponsonby, 1st Earl of Bessborough Letitia Ponsonby Anne Ponsonby Folliet Ponsonby Bridget Ponsonby Siblings Sir Henry Ponsonby Folliott Wingfield, 1st Viscount Powerscourt Elizabeth Ponsonby John Ponsonby Partners Mary Moore