Archival research for descendants of Jewish families from pre-war Poland presents additional challenges, as a significant portion of local civil and religious (synagogue) records were destroyed during the Holocaust. In many cases, the necessary information must be sought through alternative sources, such as international Jewish genealogical databases, records of immigration organizations, and the state archives of neighboring countries where areas of pre-war Poland are now located.
The legal principle of the unbroken genealogical chain continues to apply in full in these cases as well, regardless of the additional difficulties in archival documentation.