Antony IV of Constantinople

Antony IV of Constantinople was the Ecumenical Patriarch of Constantinople for two terms, from January 1389 to July 1390, and again from September 1390 until his death.
He was originally a hieromonk, possibly from the Dionysiou monastery in Mount Athos. He was deposed during the usurpation of John VII Palaiologos in July 1390, and replaced by Macarius of Constantinople, who had already served in the office in 1377–1379. After the restoration of John V Palaiologos and Manuel II Palaiologos a few months later, he was restored to his post.
He is notable for his correspondence with Władysław II Jagiełło, Grand Duke of Lithuania, urging him to join in a crusade against the Turks along with the Hungarians, and with Vasily I of Moscow, to whom he defended not only the universal spiritual authority of the Constantinopolitan patriarchate, but also the universal authority of the Byzantine emperors, regardless of the actual diminished state of the Byzantine Empire.