The 1870s one.
An example of the dictatorship of the proletariat.
Didn't last long (70ish days).
Not completely Marxist, not completley anarchist. It had its own thing going on. (And existed before these distinctions were that clear, anyway).
Marx’s observation in the context of his analysis of the lessons of the Paris Commune, that 'the working class cannot simply lay hold of the ready-made state machinery, and wield it for its own purposes' - is hard to miss.