1. FC Union Berlin is a professional German association football club based in Berlin. The club emerged 1966 under the current name in East Germany and plays in the 2. Fußball-Bundesliga. The home ground Stadion An der Alten Försterei is the largest single-purpose football stadium in the German capital. It has been home to Union Berlin and its forerunners since it was opened in 1920. The club is famous for its enthusiastic and creative fan base and is colloquially called "Eisern Union".