248758
After disintegration of the Principality of Chernigov in the wake of the Mongol invasion of Rus ' , Belyov became a seat of a local princely dynasty .
 Belyov
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Belyov