Principality of Smolensk
In 1356 Algirdas took region of Bryansk, which included Trubetsk and Starodub, from Principality of Smolensk and granted to his son Dmitry to govern it. The territory was in far north east from the heartlands of the Grand Duchy of Lithuania and bordered the Grand Duchy of Moscow. In 1370 Dmitri Donskoi, Grand Duke of Moscow, unsuccessfully attempted to conquer the territory. In 1372 Dmitry witnessed Treaty of Lyubutsk between Algirdas and Dmitri Donskoi.