Julius Friedrich Leopold Rupp was a Prussian Protestant theologian. He founded the first Free Protestant Congregation in Königsberg, which rejected all state or church control and believed in absolute freedom of conscience for its members.

The Gustav-Adolf-Werk (GAW) is a society under the roof of the Evangelical Church in Germany (EKD) which has for its object the aid of feeble sister churches and congregations. It is responsible for the taking care of the diaspora work of the EKD, in cooperation with the EKD itself, its member churches and congregations. The organization started with a focus on the diaspora, but has separate branches internationally in the meanwhile. The organization in Austria is still called the Gustav-Adolf-Verein, which was the original name in Germany as well. Further terms used for the GAW in the past include Gustavus Adolphus Union, Gustav-Adolf-Stiftung and Evangelischer Verein der Gustav-Adolf-Stiftung.