Who is important in the Age of Faith?

There are many great men and women who lived in the time period of our 3rd Unit (600-1450). For a cool 15 points all you have to do is choose a person and say what it is that makes that person so importtant to world history (I think a paragraph of facts and a paragraph of your opinion would be sufficient. The trick is that people can only be used once.

Happy effort! We'll keep this going up to November 8.