In late 1922, however, as a result of the Upper Silesia plebiscite, Bytom remained part of Germany and the club ceased to exist.
In May 1945, numerous players and officials of another Polish club, Pogoń Lwów, arrived in Bytom and decided to revive Polonia.
It performed well in the Intertoto Cup, reaching the final in the 1963–64 season after defeating teams such as Red Star Belgrade, Sampdoria and fellow Polish side Odra Opole.
It won the trophy in the 1964–65 season after defeating teams like RC Lens, Schalke 04, Liège and SC Leipzig.
Many of the other supporters groups were travelling to Bytom only to watch how Polonia's fans are cheering their club and behaving on the stadium.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.