Was your qualifying ancestor registered in Latvia's People's Register on or before June 17, 1940?

June 17, 1940 is the anchor date for Latvian citizenship by descent, it is the day before Soviet forces completed the occupation of Latvia on June 18, 1940. Registration in the People's Register on or before that date is the primary proof of Latvian pre-occupation citizenship. This document was the official population register maintained by the independent Latvian state.