Jagiellonia Białystok ( Polish pronunciation: [jaɡʲɛ(l)ˈlɔɲa bjaˈwɨstɔk] ) is a Polish professional football club based in Białystok that plays in the Ekstraklasa , the top level of Polish football . The club was founded in 1920 by soldiers in the 42nd Infantry Regiment Reserve Battalion in Białystok. Jagiellonia play their home games at the Chorten Arena .