Final answer:
The name Sir Edmund (IV) Mortimer does not appear in the provided text excerpts, suggesting the question may refer to a historical figure not mentioned in the text.
Step-by-step explanation:
The question refers to a historical figure, Sir Edmund (IV) Mortimer, who is not directly mentioned in the provided text excerpts. There are no occurrences directly related to Sir Edmund in the references given, which implies that the student may be inquiring about a different context or could have confounded the name with another character in literature or history. If the student is referring to the historical figure Sir Edmund Mortimer, he was a notable English nobleman involved in the Welsh Revolts against King Henry IV of England and is known for the part he played in the politics of the time, including his capture and subsequent defection to the Welsh.