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).
Hereditary peer
In the Scottish peerage, the lowest rank is "lordship of Parliament", the male holder thereof being known as a lord of Parliament. A Scottish "barony" is a feudal rank, and not of the Peerage. The barony by tenure or feudal barony in England and Wales was similar to a Scottish feudal barony, in being hereditary, but is long obsolete, the last full summons of the English feudal barons to military service having occurred in 1327. The Tenures Abolition Act 1660 finally quashed any remaining doubt as to their continued status.