In 1312, Charles besieged Sáros Castle, (now part of Slovakia - Šariš Castle) controlled by the Abas. After the Abas received additional reinforcement from Máté Csák (according to Chronicon Pictum almost Máté's entire force as well as 1,700 mercenary spearmen), Charles Robert of Anjou was forced to retreat to the loyal Szepes county (today the region of Spiš), whose Saxon inhabitants subsequently reinforced his own troops. The Abas benefited from the retreat. They decided to use the gathered opposition forces to attack the town of Kassa (today Košice) because of its strategic importance. Charles marched on Kassa and engaged his adversaries. The Battle resulted in a decisive victory for Charles.

The immediate consequence was that Charles Robert of Hungary gained control over the northeastern part of the country. But the long-term consequences of the victory were even more important. The battle drastically reduced magnates' opposition against him. The King extended his power base and prestige. The position of Charles Robert as King of Hungary was now secured militarily and resistance against his rule came to its end.