Capital of Germany’s state of Saarland / 1815 location of the Saarbrücker Union, the first union between Reformed and Lutheran congregations / 1817-21 subsequent formation of United Churches in many parts of Germany, mostly as an administrative union, in some places even as a full union of confession / 2004 latest union of two Reformed and a Lutheran church led to the Protestant Church in the Netherlands

Photo: flickr/Wolfgang Staudt