Charles won his first decisive victory in the Battle of Rozgony (at present-day Rozhanovce in Slovakia) on 15 June 1312. After that, his troops seized most fortresses of the powerful Aba family. During the next decade, Charles restored royal power primarily with the assistance of the prelates and lesser noblemen in most regions of the kingdom. After the death of the most powerful oligarch, Matthew Csák, in 1321, Charles became the undisputed ruler of the whole kingdom, with the exception of Croatia where local noblemen were able to preserve their autonomous status. He was not able to hinder the development of Wallachia into an independent principality after his defeat in the Battle of Posada in 1330. Charles's contemporaries described his defeat in that battle as a punishment from God for his cruel revenge against the family of Felician Záh who had attempted to slaughter the royal family.