Gregory Tsamblak^[a] (c. 1365 – c. 1420), member of the Tzamplakon family, was a Bulgarian writer and cleric active in Bulgaria, Moldavia, Serbia, Grand Duchy of Lithuania, and the Principality of Kiev.

He was born into the Tzamplakon family in the Bulgarian capital of Tarnovo around 1364/1365.^[1]

During his sojourn in Serbia he wrote a biography of Stephen Uroš III, a hymn for the church service honoring Stefan of Dečani, and a report on the transfer of the remnants of Saint Paraskeva to Serbia, for which he also rewrote the service.^[2]

In 1414, Grand Duke Vytautas attempted to re-establish the Metropolis of Lithuania. He arranged for a synod of bishops to elect Gregory as the Metropolitan of Lithuania.^[3] The consecration took place without the consent of Patriarch Euthymius II of Constantinople who deposed and anathematized him and who confirmed the same in letters to Metropolitan Photius of Kiev, Emperor Manuel II Palaeologos and Grand Prince Vasily I. After Gregory’s death in the winter of 1419–1420, Photius made peace with Vytautas. As a result, the entire Metropolis of Kiev and all Rus', including Halych, was unified under Photius until his death in 1431.^[1]

The rivalry between Vilnius and Moscow effectively ended in 1448 when Moscow began selecting the metropolitans independently without approval from the Ecumenical Patriachate, which collapsed in 1453.^[4][1]

• Constantine of Kostenets
• Dimitar of Kratovo
• Nicodemus of Tismana
• Anonymous Athonite
• Patriarch Evtimiy

• Rowell, Stephen Christopher (1994). Lithuania Ascending: A Pagan Empire Within East-Central Europe, 1295–1345. Cambridge: Cambridge University Press. ISBN 978-1-107-65876-9. Retrieved 14 July 2021.

• Gregory Tsamblak at Encyclopedia of Ukraine