<P> He had the greatest military potential of the 14th century with his enormous armies (often over 100,000 men). Meanwhile, Poland's attention was turned eastwards, as the union with Lithuania created an enormous entity in the region . The union, and the conversion of Lithuania, also marked the end of paganism in Europe . </P> <P> Louis did not leave a son as heir after his death in 1382 . Instead, he named as his heir the young prince Sigismund of Luxemburg . The Hungarian nobility did not accept his claim, and the result was an internal war . Sigismund eventually achieved total control of Hungary and established his court in Buda and Visegrád . Both palaces were rebuilt and improved, and were considered the richest of the time in Europe . Inheriting the throne of Bohemia and the Holy Roman Empire, Sigismund continued conducting his politics from Hungary, but he was kept busy fighting the Hussites and the Ottoman Empire, which was becoming a menace to Europe in the beginning of the 15th century . </P> <P> The King Matthias Corvinus of Hungary led the largest army of mercenaries of the time, The Black Army of Hungary, which he used to conquer Bohemia and Austria and to fight the Ottoman Empire . However, the glory of the Kingdom ended in the early 16th century, when the King Louis II of Hungary was killed in the battle of Mohács in 1526 against the Ottoman Empire . Hungary then fell into a serious crisis and was invaded, ending its significance in central Europe during the medieval era . </P> <P> The state of Kievan Rus' fell during the 13th century in the Mongol invasion . The Grand Duchy of Moscow rose in power thereafter, winning a great victory against the Golden Horde at the Battle of Kulikovo in 1380 . The victory did not end Tartar rule in the region, however, and its immediate beneficiary was the Grand Duchy of Lithuania, which extended its influence eastwards . </P>

Feudalism flourished at its peak during what subdivision of medieval europe