On his return trip to Constantinople, Jeremias also visited the Polish–Lithuanian Commonwealth. In agreement with King Sigismund III Vasa, he deposed the Metropolitan Onesiphorus Devochka [ru; uk], probably because he was a digamy (the second marriage for priests) and he tolerated this use.[3] King Sigismund, under the advice of such magnates as the voivode of Navahrudak (Teodor Skumin-Tyszkiewicz) and the voivode of Kiev (Konstanty Ostrogski),[1] put forward Michel Rohoza as his candidate for the metropolis. In August 1589 at Vilnius, Jeremias consecrated Michel as Metropolis of Kiev, Halych and all Rus'.[4][5]
As Metropolitan, he started to reform the Church. He wished to improve the mores of the clergy and to reduce of the meddling of lay people (and of confraternities) in the life of the Church and in monasteries. To this end, he summoned a synod in 1590. His attempts of reform were opposed by the stauropegics. Since it proved difficult to carry on the reforms, he began to look to Rome.[6]
In 1590, Metropolitan Rohoza with all his suffragan bishops, subscribed to a document that solicited a union with Catholic Church on condition that this union of faith would preserve the Byzantine rite, the liturgical practices and the canon law of the metropolis. This was agreed and was formalized in a document on 2 December 1594 and again in two petitions, one to the king and one to Pope Clement VIII, undersigned in Brest on 12 June 1595. This Union of Brest, as it became known, was formally proclaimed 8 October 1596. While Rohoza signed the union, he later tried to hinder its action, but without results.[7]
Rohoza died between June and August 1599. He was succeeded by the bishop of Volodymyr, Hypatius Pociej, a fierce supporter of the union. Not all the Ukrainians supported the union, and twenty years later, in 1620 the Patriarch of Jerusalem re-established a Kievan Metropolia under his own jurisdiction, which first Metropolitan was Yov Boretsky, so duplicating the hierarchy.
^The title is also known as the Metropolis of Kiev, Halych and all Rus' or Metropolis of Kyiv, Halychyna, and All-Rus'. The name "Galicia" is a Latinized form of Halych, one of several regional principalities of the medieval state of Kievan Rus'.