Years: 1812–1868
Primary city: Utena
Rabbi Avraham Tzvi Hirsch Eisenstadt, known from Byelostok, authored the influential Pitchei Teshuvah, a comprehensive index to the responsa and decisions of acharonim on the topics of the Shulchan Aruch. A descendant of Rabbi Meir Eisenstadt, author of the Panim Me'irot, he served as rabbi in several communities in the Russian Empire. The work remains a standard reference in halachic study.