I thought the PL-commonwealth as a predecessor of the EU.
You heard founders of EU. No, its not on the heritage on anything Polish and Slavic, old European feith, etc. Its Jewish, Christian, and now also Islamic, etc. That`s them.
When we have Central European Union it would be founded on the heritage of European Sarmatia, Scordisci-Boii tribal alliance, Samo`s Empire, Great Moravia, Polish-Lithuanian Commonwealth, Serbian Empire (because encompased entire Balkan and parts of Central and Eastern Europe, liberating Slavs from Western and Eastern Romans), Yugoslavia, Czechoslovakia, Visegrad Group. Then we can also say on the spirit of old Slavic feith and Christianity. That`s us.