Anthypatos (Greek: ἀνθύπατος) is the translation in Greek of the Latin proconsul. In the Greek-speaking East, it was used to denote this office in Roman and early Byzantine times, surviving as an administrative office until the 9th century. Thereafter, and until the 11th century, it became a senior Byzantine court dignity.
In the late Roman and early Byzantine Empire, the title of anthypatos was borne by the governors of a few special provinces (Asia, Africa, Achaea and also Constantinople between 330 and 359) through to the 7th century, when the late Roman administrative system was replaced by the themata.
The title then was used within the context of the thematic structure: thematic eparchoi kai anthypatoi ("eparchs and proconsuls") are still in evidence in Asia Minor until the early 9th century, functioning as civil governors, possibly under the authority of the (much reduced in power) praetorian prefect in Constantinople. At this point, the term also began being used as a rank and dignity rather than an office: Theophanes the Confessor records that Emperor Theophilos (r. 829–842) honoured Alexios Mousele, the husband of his daughter Maria, by naming him "patrikios and anthypatos", raising him above the ordinary patricians. This change coincided with the abolition of the last vestiges of the old Roman system, as the provincial anthypatoi as civil governors were abolished, and replaced by the stratēgos of the thema, and in their role as overseers of army provisioning and financial matters, by the much less prestigious prōtonotarioi.
Thus, from the latter part of Michael III's reign (r. 842–867), the term became a regular dignity intended for "bearded men" (i.e. non-eunuchs), constituting a class above the patrikioi. The full title anthypatos kai patrikios was henceforth conferred upon several high-ranking administrative and military officials throughout the 10th and 11th centuries. In the 11th century, there is also evidence of a prōtanthypatos (πρωτανθύπατος, "first anthypatos"), and a single occurrence of a disanthypatos (δισανθύπατος, "twice anthypatos"). All these dignities disappeared, however, in the early 12th century.
According to the Klētorologion of Philotheos, written in 899, the insignia of office of the anthypatos were purple inscribed tablets. Their award by the Byzantine emperor signified the elevation of the recipient to the office.