The title of ek prosopou (Greek, Modern (1453-);: {{lang|grc|ἐκ προσώπου), meaning "representative", was widely used in the middle Byzantine Empire (9th–12th centuries) for deputies of various office holders.
The title could be applied in a generic sense to any senior official, such as the strategos of a theme, who was in a sense the deputy of the Byzantine Emperor. In a more technical sense, as used in the Taktika or lists of offices of the 9th–11th centuries, it was used by subordinate officials who deputized for a strategos or other provincial governor or one of the central government ministries for a specific district (called ekprosopike by Kekaumenos). The same usage is also attested in the ecclesiastical hierarchy.
. J. B. Bury . The Imperial Administrative System of the Ninth Century - With a Revised Text of the Kletorologion of Philotheos . 1911 . London . Oxford University Press . 46–47.