There was beautiful rapport on Serbian TV about Kashubs, native Europeans. It was about Kashubian past, present and future. They suffered greatly under the Germanic yoke and later also, what surprised me, got injustice from Poles, too. It should be contradiction in itself but I kind of understand reasons.
From all Slavic languages Kashubian is closest to Serbian language and it is even logical. Kashubs and Serbs perfectly understand each others. Kashubs are remain of that first Sarmatian (ie Serbian) backbone that stretched from Balkan ice age refugium, via Lusatia, to the Baltic- in old records known as Serbian ocean (Oceanus Sarmaticus). In past Kashubs held entire coast of Baltic sea. In old Roman records, Kashubs are those Serbs Serbs, while bulk of populace of other Sarmats were considered to be younger offspring of that original Balkan-Baltic backbone. In fact they are in great deal paternal (older/ancestral) population to Poles. They are those Sarmats remembered in Polish legends as ancestral Sarmatian/Arian population. They other parts of Polish lineage coming from Crimean ice age refugium, Black sea (that was in fact lake 5000 years ago) and even more eastern all the way to Siberia (that in past had its warmer phases).
Video above speak of old German sources that mention Kashubs as `Slavinjaci` or `Kashubian Serbs` (video on 16:50). On video 3:05, Kashub says that German Rugen was in past named Rujan and was most important religious site of Svetovid... Grafitovic nobles ruled Rujan at a time of free Arkona... that Danes destroyed Rujan because Kashubs held to their old faith. On video 6:50 professor Jezi Nagel speaks of deep Kashubian loyalty to Poland and Slavic world.... Kashubs are old native people in past known as Veneti, Sorabi and Vendi.