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).
Supreme Court of the United Kingdom
New judges appointed to the Supreme Court after its creation will not necessarily receive peerages; however, they are given the courtesy title of Lord or Lady upon appointment. The President and Deputy President are appointed to those roles rather than being the most senior by tenure in office.