I'm an Australian citizen and I'm investigating any possibility of getting Polish citizenship, but I think it's not very likely.

My paternal great great grandfather was born in Prussia in 1843 (in a part that became Poland after WWII), he left in 1873 (we think), my great grandfather was born in Australia in 1874. My paternal great great grandmother was born in Linken, Prussia (now Poland) in about 1846. As all of this was when Poland technically didn't exist, I assume they were all Prussian citizens??? or German? As far as I know they never obtained any other citizenship after arriving in Australia. My grandfather, my father and I were all born in Australia.

I am guessing that there is probably no chance of me getting Polish citizenship, given that it was all so long ago, and that the ancestors who came from Poland lived there when it was controlled by other countries. But I've seen a few posts from people saying they got citizenship because a grandparent or great grandparent was Polish, so possibly could my father get Polish citizenship (or confirm it) and then me?

Also I'm trying to find more documentation about these ancestors. Does anyone know where I can get records of things in Poland so long ago? In Australia or somewhere in Europe, as I currently live in the Netherlands.

Thanks very much for your help!