| Patriarch Of: | Ecumenical Patriarch of Constantinople |
| Enthroned: | 837 |
| Ended: | 843 |
| Religion: | Chalcedonian Christianity |
John VII, surnamed Grammatikos or Grammaticus, i.e., "the Grammarian" (Greek: Ἰωάννης Γραμματικός, Iōannīs Grammatikos; died before 867), was Ecumenical Patriarch of Constantinople from January 21, 837 to March 4, 843, died before 867. He is not to be confused with the much earlier philosopher John Philoponos.
John was born into an aristocratic family of Armenian descent.[1] His father was Pankratios Morocharzanios, and he had a brother, Arsaber. Warren Treadgold identifies the latter as Arsaber, who married a sister of Empress Theodora, wife of Emperor Theophilos. John's sister was the mother of the future Patriarch Photios.[2]
John, who began his clerical career c. 811, was also a painter of icons and a correspondent of Theodore of Stoudios. By 814 John had become an iconoclast, and Emperor Leo V chose him to head a committee to collect patristic texts supporting this theological position in preparation for the Synod of 815, which reinstated iconoclasm. John was rewarded for his efforts by being appointed abbot of the prestigious monastery of Sergius and Bacchus (now the Little Hagia Sophia), where recalcitrant iconodules were re-educated.
John was known for his learning (hence his nickname Grammatikos) and for his persuasive rhetoric in the endless debates that are a favorite subject of hagiographic sources reflecting the second period of the Iconoclasm. John was also charged with tutoring the future Emperor Theophilos during the reign of his father, Michael II, and is credited with instilling strong iconoclastic sympathies in his pupil. Upon Theophilos' accession, John was appointed synkellos (assistant to the patriarch), a position that made him a likely heir to the patriarchate. In c. 830, John was sent on an embassy to the Abbasid caliph al-Ma'mun, but this did little to prevent a period of fierce warfare between the Byzantine Empire and the Abbasids. He did, however, bring back a plan of the Abbasid palace in Baghdad for his emperor's amusement, and oversaw the construction of a similar structure in Bithynia.
The circumstances of John VII's patriarchate are unclear. Appointed patriarch in 837[3] by his disciple Theophilos, he may have been responsible for a slight increase in the persecution of the iconodules. He was deposed in 843 by Theophilos' widow, Theodora, his own relative, as a prelude to the end of iconoclasm. The deposed patriarch survived until the 860s.