This is a self-portrait of which artist?

The term that refers to circular barrel-vaulted passages is:

This image is from the:  

What is the name for the underground cemeteries of the early Christians?  

The title of this painting is:  

This type of vase is an example of?  

Which palace was not fortified?

The first Holy Roman Emperor was?

The architect of this monument was:

Illuminated manuscript pages are made of: