The topic of the relationship between state and religion in Europe is obviously very ample and comprehensive. It is evident, too, that the topic is to some extent vague, a condition that allows for a global survey. Religion and the divine in different shapes accompany all human history, and man was perennially looking for adequate ways to express his relationship to God and the divine. With regard to the three monotheistic world religions Judaism, Christianity, and Islam, the Old Testament bears already witness of the relationship between state and religion. The New Testament and the subsequent history of occidental Europe build first on that basis, but then distance themselves considerably from it. The following essay gives an outline of that relationship, stressing both continuities and differences. By giving an overview of the relationship between state and religion I will first enter the field of history. The first part deals with selected events in occidental history, addressing actual historical events as well as underlying thoughts and ideas. The second part sheds some light on the relationship between state and religion in the 20th and 21st century, taking into consideration the constitution of the Federal Republic of Germany as well as the role of religion in the European Union. A short statement will conclude the account of the relationship.