persisted into the 19th century in the Holy Roman Empire, and these domains (principalities, etc.) exhibited many of the characteristics of sovereign states. Prior to 1866 Prussia alone consisted of more than 270 discontiguous pieces of territory.

Residing in an enclave within another country has often involved difficulties in such areas as passage rights, importing goods, currency, provision of utilities and health services, and host nation cooperation. Thus, over time, enclaves have tended