The combined Dumbarton Oaks and Fogg collection of Byzantine seals is one of the largest in the world, containing 17,000 specimens. Volume 6 in the catalogue presents the seals of emperors and patriarchs of Constantinople. Imperial seals are presented in conjunction with a representative coin of the appropriate emperor or empress to help the reader compare the iconography. Also included are select seals from patriarchs of Constantinople. More than 250 seals are illustrated and accompanied—where appropriate—by a full commentary regarding each specimen's date, biographical information on its owner, peculiarities of orthography, and iconographic features. These seals contribute significantly to historical geography, the evolution of the Byzantine imperial administration, development in the Greek language, and decorative vogues.