328704
Even when Theodosius I made Christianity the official religion of the empire the caves offered protection for the local people during raids by the Sassanid Persians circa 604 AD and by the Islamic Caliphate circa 647AD .
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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:
 None