[2] During the Russian Revolution of 1905 local revolutionists led by Dāvids Beika stormed his residence at Dobele German pastorat and burned his library and archive.

As editor of the major Latvian language newspaper Latviešu Avīzes and a member of the St. Petersburg Academy of Sciences, Bielenstein was the author of numerous major works on linguistics and ethnography, including Die lettische Sprache, nach ihren Lauten und Formen (The Latvian Language, Its Phonetics and Forms, 2 volumes, 1863–64) and Die Grenzen des lettischen Volksstammes und der lettischen Sprache in der Gegenwart und im 13.

He encouraged the collection of dainas, studied traditional wooden architecture, and examined castle mounds to identify them according to their description in ancient chronicles.

His friendship with Wilhelm Mannhardt led to an interest in Latvian mythology and folk psychology.

[2] Bielenstein married Ernestine Louise Hermine Van Bordelius and they had nine children, six of which survived to adulthood.