Dukes in the United Kingdom
Duke, in the United Kingdom, is the highest-ranking hereditary title in all four peerages of the British Isles. A duke thus outranks all other holders of titles of nobility (marquess, earl, viscount and baron).
Peerage of Ireland
In the following table of the Peerage of Ireland as it currently stands, each peer's highest titles in each of the other peerages (if any) are also listed. Irish peers possessed of titles in any of the other peerages (except Scotland, which only got the right to an automatic seat in 1963, with the Peerage Act 1963) had automatic seats in the House of Lords until 1999.