[1] In 1245, King Daniel of Galicia won a decisive battle over the Hungarian-Polish army of his opponent Rostislav Mikhailovich and united Halychia with Volhynia.
In reaction to this move, King Daniel's son and successor on the throne — Leo I — petitioned the Ecumenical Patriarch to erect a new metropolis in the territory of his kingdom.
Leo died in 1301 but his son — Yuri I of Galicia — succeeded in securing the charter of establishment from Patriarch Athanasius I of Constantinople with the approval of Emperor Andronikos II Palaiologos.
A Catholic from the Polish Piast dynasty — Yuri II Boleslav — succeeded to the throne of Halych.
Theognostus and the Grand Dukes of Moscow wanted to get rid of a rival metropolis in Rus' lands.
Following his death in 1347, the Grand Prince of Moscow — Simeon — conspired with Theognostus of Kiev to convince Emperor John VI Kantakouzenos to disestablish the Halych metropolis.
The territory of the former metropolises of Halych and of Lithuania were officially lowered to the rank of bishoprics within the Kiev metropolis.
Just before his death, King Casimir III the Great of Poland revived the Halych metropolis for a short period.
He convinced Philotheus I, who served as Patriarch of Constantinople for the second time, to consecrate Antoniy as Metropolitan of Halych.
In May 1371, he wrote to Alexius informing him that he had separated the Halych (Galician), Kholm, Turov, Peremyshl, and Vladimir-Volhynia dioceses from the Kiev metropolis for the third time.
It may also have been motivated by a desire to advance his calls for a separate metropolis for the Grand Duchy that was independent of Moscow.
The rivalry effectively ended in 1448 when Moscow began selecting the metropolitans independently without approval from the Ecumenical Patriarchate, which collapsed in 1453.