Polonia BytomPolonia Bytom were the first Polish club to get past the preliminary round of the European Cup of national champions - a feat no other side from Poland could match at the time. The club was founded on 4 January 1920, when a founding meeting established the Towarzystwo Sportowe Polonia, answering a call from the Polish Plebiscite Commissariat for Polish sporting and cultural organisations to be set up in Upper Silesia. The club's activity was interrupted in 1922 when the region was divided between Poland and Germany, forcing Bytom's officials and players to relocate to Chruszczów and Miechowice, where they kept their sporting tradition alive under a different name. The club did not return to its home city of Bytom until May 1945, when it was reactivated under chairman Jan Wilga, its ranks soon swelled by players and officials arriving from disbanded clubs in Lwów.
Polonia's golden era fell in the 1950s and 1960s, when the club won the Polish championship twice - in 1954 and in 1962, in a shortened, spring-only season decided by a two-legged tie against Górnik Zabrze, won thanks to four goals from Jan Liberda and Ryszard Pogrzeba. As early as 1958, becoming the first Silesian club to play in European competition, Polonia appeared in the European Cup of national champions, going out in the first round after two 0-3 defeats to Hungary's MTK Budapest. Four years later, now defending its national title, the side eliminated Greek club Panathinaikos in the qualifying round, becoming the first Polish club to reach the tournament's proper first round, though it lost in the next stage to Turkey's Galatasaray. The team's goal was defended at the time by legendary keeper Edward Szymkowiak, a repeat top scorer among goalkeepers and the man after whom the club's current stadium is named.
The high point of Polonia's European history came in 1965, when the club won the Rappan Cup (Intertoto), beating East German side SC Leipzig in a two-legged final - after losing 0-3 away, Bytom overturned the deficit at home, winning 5-1 to remain, to this day, the only Polish football club ever to lift a European trophy. Having produced 26 full Poland internationals, including five Olympians, the club's fortunes declined from the early 1980s onward, and it spent most of the following decades in the lower divisions, with a brief return to the Ekstraklasa between 2007 and 2011. After years of rebuilding, Polonia won promotion to the I liga in the 2024-25 season, continuing under the banner of restoring Bytom football to a higher level of competition.