What is a Pro-Chancellor? I was looking at a document describing setting arrangements for a ceremony and ran into the phrase: 


  The president of the Student Guild shall sit in the front row, with
  the Vice-chancellor, the Chancellor, and the Pro-Chancellor


What is a Pro-chancellor?
I've never heard of one before.

In-case this is a regional term, I am at a Australian university.
A "pro-chancellor" (or similarly a "pro-rector," which we have in Germany), is a deputy to a chancellor (or rector), who handles certain duties on behalf of the chancellor (or rector). In the particular case of Commonwealth countries from which you hail, the pro-chancellor is the person who heads the university's executive council on behalf of the chancellor.