For the sake of good-faith discourse, what are some historical examples of Anarcho-Capitalist and/or free market societies?

I realized if I’m going to continue debating ancaps on this sub and elsewhere I should know the historical examples of anarcho-capitalist/free market societies. I think it’s important to ask actual anarcho-capitalists for their preferred examples because as a marxist it’s really annoying when people bring up examples of state-capitalism as communism as if their aren’t plenty of historical examples of communist ideas being implemented in history.

So I want to know from you guys: what are your favorite examples of free-markets in history. And what, in your opinion, is the reason for their failure?

As always, thanks in advance for any answers. 🙂