Which frontier is characterized by the division between Catholic/Protestant Western Christianity and Eastern Orthodoxy?

The division characterized by the separation between Catholic/Protestant Western Christianity and Eastern Orthodoxy is aptly referred to as the Religious Limes. This term highlights the significant cultural, historical, and theological divisions that have existed within Christianity, particularly as they relate to the geographical and political boundaries that emerged in Europe.

The Religious Limes can be traced back to the Great Schism of 1054, which formally separated Eastern Orthodoxy from Western Christianity, eventually leading to various theological disputes and the Protestant Reformation in the 16th century. These divisions have played a crucial role in shaping the socio-political landscapes of Europe over centuries.

In contrast, the other terms, while they represent various forms of borders or divisions, do not accurately encapsulate the specific religious context. The Roman Limes refers to the boundary of the Roman Empire, primarily related to military and administrative concerns. The Ottoman Limes relates to the frontiers that defined the Ottoman Empire's reach and influence, while the Iron Curtain symbolizes the political and ideological divide during the Cold War. None of these options encompass the nuanced religious differences signified by the Religious Limes.