Sympoliteia
A sympoliteia (), anglicized as sympolity, was a type of treaty for political organization in ancient Greece. By the time of the Hellenistic period, it occurred in two forms. In mainland Greece, the term was often used for a federal state consisting of individual "poleis" (city-states) with shared political institutions and citizenship. Examples of this are the Achaean League and the Aetolian League. The term was also used for the political merger of two or more neighboring "poleis". This could eventually, but not necessarily, lead to the disappearance of one of the participating "poleis". This second form was especially  common in Hellenistic Asia Minor. A "sympoliteia" is often contrasted with an "isopoliteia", a treaty which granted equal citizenship to the citizens of the participating "poleis" but maintained their political independence. Contemporary writers of the Hellenistic period could use the term loosely, Polybius for example used the term "sympoliteia" to refer to the shared citizenship granted by both treaties. In similar fashion there was also considerable overlap between the concepts of synoecism and "sympoliteia".