1649
Since the Anglo-Saxons took over the region in the 8th century , it has stretched between the River Monnow and River Wye , but it derives from the once much larger Welsh kingdom of Ergyng .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None