Irredentism is one state's desire to annex the territory of another state. This desire can be motivated by ethnic reasons because the population of the territory is ethnically similar to or the same a
Kurdish inhabited area by CIA box inset removed
The Megali Idea was a Greek nationalist and irredentist concept that expressed the goal of reviving the Byzantine Empire, by establishing a Greek state, which would include the large Greek populations
Irredentism
…theorists see irredentism as a more recent phenomenon. The term was coined in the 19th century and is linked to border disputes between modern states. The Megali Idea was a nationalist and irredentist project that shaped Greek history from the War of Independence in the 1820s through the Balkan Wars in the beginning…
Constantine I of Greece was called Constantine XII by his supporters, the purported successor to the Emperor Constantine XI Palaiologos
Eleftherios Venizelos tried to realize the Megali Idea
Poster celebrating the "New Hellas" after the Balkan Wars.
Greek soldiers in Smyrna, May 1919.