I went to watch England v Slovakia in Bratislava (popn. 431,000) in October 2002 and bought a ticket on the black market from a tout for the Slovakia end. I walked into the Slovakia end of the stadium (where there were 30,000 fans present) and randomly stood in front of an ENGLISH man who lived and worked in the city. He said he could tell I was English, and we got chatting.
It turned out that, like me, he supported AFC Bournemouth, which was where his parents lived.