Henry Brooke Parnell, 1st Baron Congleton PC, known as Sir Henry Parnell, Bt, from 1812 to 1841, was an Irish writer and Whig politician. He was a member of the Whig administrations headed by Lord Grey and Lord Melbourne of the 1830s and also published works on financial and penal questions as well as on civil engineering. He was a grand-uncle to the Irish nationalist leader Charles Stewart Parnell.

Charles Stewart Parnell was an Irish nationalist politician who served as a Member of Parliament (MP) in the United Kingdom from 1875 to 1891, Leader of the Home Rule League from 1880 to 1882, and then of the Irish Parliamentary Party from 1882 to 1891, who held the balance of power in the House of Commons during the Home Rule debates of 1885–1886. He fell from power following revelations of a long-term affair, and died at age 45.