Austria is more or less at the Western end of the Danube. Troy is just across the sea from the Danube estuary on the Black Sea.
The Danube is the link.
I recommend that you simply go to google.com and type in Brezh. That will pop up about a million "Celtic Ring" website. Start reading.
Hey Muawiyah. Does Brezh have ANY connection with a schmuck named Brezhnev? There has got to be a link there somewhere.