There have been two Duke Baronetcies; both are now extinct. The first created 16 July 1661 for Edward Duke in the Baronetage of England, the second created 5 December 1848 for James Duke in the Baronetage of the United Kingdom.
Contents
Duke of Benhall, Suffolk (1661)
Duke of London (1849)
References
Duke baronets Wikipedia(Text) CC BY-SA