15504
1407 as the fifth son of the Byzantine Emperor Manuel II Palaiologos ( reigned 1391–1425 ) and his wife Helena Dragaš .
 Byzantine Emperor, Manuel II Palaiologos, Helena Dragaš
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Byzantine Emperor, Manuel II Palaiologos, Helena Dragaš