Not quite the same thing, but: between 1918 and 1921, there was an 'anarchist territory' with a population of 7 million people in eastern Ukraine. By all accounts it was essentially stateless and had no real authority. Alas, it got entangled in the Russian Civil War and was dismantled in the 1921 by the Soviets.

https://en.wikipedia.org/wiki/Makhnovia