I'm currently in the process of retrieving a polish citizenship from my great grandfather.
He was born in Poland and lived there for decades as a citizen.
I've contacted some polish archives but unfortunately, I don't have his birth certificate.
According to the law, he is eligible for a polish citizenship (never served in a foreign army, etc).
I do have, however, lots of other documents related to him\his relatives other than his own birth certificate.
Currently I do possess his marriage certificate and a migration document which mentions that he left Poland in 1935 (and I assume - his last place of residence).
More than his marriage certificate and that migration control certificate, I do also have:
A permanent residence certificate of his wife.
A permanent residence certificate of his father.
A birth certificate of his father (and maybe a birth certificate of his wife & mother).
Both his wife and parents were Polish citizens.
My question is - according to the Polish law, would that be enough to prove his Polish roots? (in order to eventually claim a Polish citizenship).