Conversation so far:
what did Matthew Paris do as a historian?
Paris continued the history on the plan which his predecessors had followed.
what was the history that the predecessors had followed?
He derived much of his information from the letters of important people.
what did he write about?
from conversation with the eyewitnesses of events.

Question: did he write about anybody important in history?
Self-contained rewrite: Did Matthew Paris write about anybody important in history?