Under Polish-Lithuanian Rule

Gradually, the western nations achieved military parity by learning from Mongol tactics and weaponry. In 1349, the Mongols lost their grip on Ukraine. Ukraine was not actually liberated, though, but assimilated (politically) by the Polish-Lithuanian empire.

Another power was rising in the west. After centuries of bloody battles against each other, Poland and Lithuania amalgamated to fight against everyone else (especially Hungary, at that point). In 1386, by a typically serpentine medieval set of dynastic inhertitances and marriages, Lithuania’s Grand Duke Jogaila became both ruler of Lithuania and, simultaneously, the King of Poland. This dual-persona empire continued informally for almost 200 years, and their eventual “formal” treaty of union at Lublin in 1569 simply ratified the fact that they had become a juggernaut state with more than eight million people. Lublin had, ironically, once been a Kyivan Rus’ stronghold. Under the logic of conquest, however, it had been reduced to just a small town in the mighty Polish-Lithuanian empire, and the memory of the Ukrainian state that it had once been part of was all but forgotten.