81278
He was proclaimed co-emperor in his youth , before 1313 , and in April 1321 he rebelled in opposition to his grandfather , Andronikos II Palaiologos .
 Andronikos II Palaiologos
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Andronikos II Palaiologos