7228
In 1137 , Barcelona and the Kingdom of Aragon were united by marriage under the Crown of Aragon .
 Barcelona, Kingdom of Aragon, Crown of Aragon
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Barcelona, Kingdom of Aragon, Crown of Aragon