Barclays bank in Brussels?

No - There used to be a Barclays around Ave Tervuren somewhere, but it wasn't a "branch" in the traditional sense of the word, it was an office in Belgium for business banking for multi nationals etc.

They do have a presence in France, but again, it's not like walking into a branch in the U.K. The French bank is a separate bank just owned by Barclays and trading under the same name.

All you need to know is on the Barclays website.