[woofie11]

We did, although we didn't experience great incarnations. The Polish-Lithuanian Empire had some aspirations along those lines, but was dominated by Poland.

Most of the Slavic cultures are culturally closer to each other than to Western Europe, although Poland has really (and rather unfortunately) westernizing since the fall of the Berlin Wall, the rise of the EU, etc. Polish culture is being replaced by Germanic culture, which is quite sad to see.

A modern pan-slavic incarnation would likely look like the USA, the EU, or some of the partnerships of African countries, where there is free trade and some degree of free travel. I think prerequisite to that would be to fix some of the governance issues in Slavic countries, though. Right now, the concern would be that any such partnership would be bullied around by Putin.