139803
A new class of advocatus thus arose , whose office , commonly rewarded by a grant of land , crystallized into a fief , which , like other fiefs , had by the beginning of the 12th century become hereditary .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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