The Icelandic Free State which existed from 930 to 1262 has often been cited as one of the few successful anarchist communities and one of the only ones to exist on a long-term "national" basis. In our timeline it was brought down by clan feuding largely sparked by external meddling from the Norwegian monarchy.
My question to anyone with more knowledge of the period than myself is how long the Commonwealth could have survived independent of Norway and with it’s decentralised, clan-based system. What effects would its survival have on the present-day island and the rest of Europe?