Smolensk, although spared the ravages of the Mongol armies in 1240, had paid tribute to the Golden Horde, gradually becoming a pawn in the long struggle between Lithuania and the Grand Duchy of Moscow.
The last sovereign monarch of Smolensk was Yury of Smolensk; during his reign the city was taken by Vytautas the Great of Lithuania on three occasions: in 1395, 1404, and 1408.
After the city's incorporation into the Grand Duchy of Lithuania, some of Smolensk's boyars (e.g., the Sapiehas) move to Vilnius; descendants of the ruling princes (e.g., the Tatishchevs, Kropotkins, Mussorgskys, Vyazemskys) flee to Moscow.
With tens of thousands of people living here, Smolensk is probably the largest city in fifteenth-century Lithuania.
Three Smolensk regiments prove decisive during the Battle of Grunwald against the Teutonic Knights.