“Where has anarchy been practiced in the world on a large scale? For how long? And to what end?”
The largest population and longest time Anarchism has been practiced was in the Catalonia region of Spain during the Spanish Civil War. For over 30 years before the civil war, the anarchist had done a very good job organizing and educating the workers and peasants. So when the military coup by Francisco Franco overthrew the government, the Anarchists were able to immediately take over many of the institutions and run them collectively. They collectivized farms and factories, redistributed land, and organized militias to fight the fascists. Many say that without the early anarchist militias, it would have just been a quick coup and not a two year civil war.
Unfortunately, the anti-fascist forces (anarchists, communists, and democratic capitalists) were ultimately defeated by Franco who had major support from Germany and Italy (who later went on to defeat many western democracies as well). The anti-fascist forces had almost zero support from the western democracies because they feared the radical Anarchist presence. The only outside forces who did help against the fascists was the USSR. However, the Communists turned on the Anarchists near the end of the war, which helped lead to their defeat.
There are many “scholarly tomes” about the Spanish Civil War. But if you’d like to read something more interesting, I’d recommend reading Homage to Catalonia by George Orwell. It’s a memoir of his time as an international volunteer in an Anarchist militia in the war. He paints an excellent picture of what revolutionary Barcelona was like and how the Anarchist militias functioned with minimal hierarchy.
There is also a very thorough BBC documentary about the Spanish Civil War. They interview anarchists, communists, and fascists who were there at the time. Most of the documentary is about the war in general, but there is one section (Part 5: Inside the Revolution) that is about the revolution and it is very interesting.
Know of other times anarchy has been practiced? Write about it in the comments!