Principality of Wallachia becomes independent

In September 1330, Charles launched a military expedition against Basarab I of Wallachia who had attempted to get rid of his suzerainty. After seizing the fortress of Severin (present-day Drobeta-Turnu Severin in Romania), he refused to make peace with Basarab and marched towards Curtea de Argeș, which was Basarab's seat. The Wallachians applied scorched earth tactics, compelling Charles to make a truce with Basarab and withdraw his troops from Wallachia. 

While the royal troops were marching through a narrow pass across the Southern Carpathians on 9 November, the small Wallachian army, formed of cavalry and foot archers, as well as local peasants, managed to ambush and defeat the 30,000-strong Hungarian army. During the next four days, the royal army was decimated; Charles could only escape from the battlefield after changing his clothes with one of his knights, Desiderius Hédervári, who sacrificed his life to enable the king's escape. Charles did not attempt a new invasion of Wallachia, which subsequently developed into an independent principality.