Investitures

http://www.fordham.edu/halsall/source/henry4-to-g7a.html

What is an investiture? Why would Henry IV, King of Germany care about this issue? Of what does he accuse Pope Gregory VII in his letter?
Read Gregory's two Bannings of Henry:
http://www.fordham.edu/halsall/source/g7-ban1.html

http://www.fordham.edu/halsall/source/g7-ban2.html

What are these bans supposed to do? Why does he ban Henry a second time?
In your opinion, what was the real issue in this controversy?

Italy

http://www.fordham.edu/halsall/source/1224artelana.html

What is an Arti? What kind of people are the members of this institution? What are the its responsibilities in this case?
Read this treaty between the cities of Florence and St. Gimignano:
http://www.fordham.edu/halsall/source/1225florence-gig.html

What are the issues this treaty addresses? Why would such a treaty exist between cities?