Wikisource has the text of the 1911 Encyclopædia Britannica article "Buckingham, Earls, Marquesses And Dukes of".
Duke of Buckingham, referring to Buckingham, is an extinct title that has been created several times in the peerages of England, Great Britain, and the United Kingdom. There were creations of double dukedoms of Buckingham and Normanby and of Buckingham and Chandos. The last holder of the dukedom died in 1889.
There have also been Earls of Buckingham and Marquesses of Buckingham.