The Turkish Federation Cup (Turkish: Federasyon Kupası) was the first professional national league in Turkey and the predecessor to the Turkish First Football League. It was organized by the Turkish Football Federation and was held in order to pick a team that would play in the European Cup. Beşiktaş J.K. won it in the 2 years it was held before it changed to the Turkish First Football League.
References
Turkish Federation Cup Wikipedia(Text) CC BY-SA