In due course, however, the Lithuanians were able to take control of a number of former Mongol territories, expand their influence in Eastern Europe, and contribute to the liberation of neighbouring peoples.
[2] In 1258–59, a joint Tatar-Rus'ian army led by Burundai launched a campaign against the Kingdom of Lithuania ruled by Mindaugas, devastating the country.
[5] Although the young Christian state has managed to withstand this incursion, it likely played a crucial role in determining its further religious orientation as Mindaugas was starting to lose his allies and pro-pagan sentiments reemerged.
The threat posed by the Mongols and lack of any meaningful support from the Roman Curia, led to Treniota and his accomplices forcing Mindaugas to renounce his union with the Livonian Order for an alliance with Alexandr Nevsky, who was a docile subject of the Tatars.
Some Lithuanian or Yotvingian warriors likely participated in the Mongol invasion of Poland in 1259, though there are no historical documents to clarify whether they did so with their leaders' permission, or as free mercenaries, or as forced troops.