Tvrtko I of Bosnia
Louis I who was heir presumptive to Casimir III of Poland assisted the Poles several times against Lithuania and the Golden Horde. The foundation of Moldavia, a Romanian principality east of the Carpathians is also connected to these campaigns. Along the southern frontiers, Louis I compelled the Venetians to withdraw from Dalmatia in 1358 and forced a number of local rulers (including Tvrtko I of Bosnia, and Lazar of Serbia) to accept his suzerainty. However, his vassals often rebelled against him in the 1360s. Bogdan, a Romanian "voivode" even achieved the independence of Moldavia. Louis I's suzerainty over Moldavia was only restored when he was elected king of Poland in 1370.