Shira Telushkin at JSTOR:
Eva Frank was born in 1756, in modern-day Ukraine, to Jacob and Hannah Frank, along with their existing children. Jacob had been raised in a family staunchly committed to the radical teachings of Shabtai Tzvi, the Jewish messianic claimant who died in 1676 after ultimately converting to Islam, and whose widely embraced prophecies and antinomian preaching—which specifically called for overturning Jewish law—nearly upended European Jewry. Around 1751, five years before Eva’s birth, Jacob proclaimed that he was Shabtai Tzvi’s successor on Earth. Building on Jewish mystical teachings and Shabtai Tzvi’s legacy, he fashioned himself as the Messiah on earth who had come to teach a new way of religious life that would bring the Messianic era. He quickly attracted thousands of followers, known as “Frankists”, and reportedly took the antinomian embrace of holy subversion even further than Shabtai Tzvi, hosting intricate rituals that overthrew the taboos of incest, menstruation, and adultery, often with the aid of sacred objects, including Torah scrolls. Though there is ongoing debate about the extent of such rituals in practice, as opposed to simply wild rumors, scholars Cristina Ciucu and Regan Kramer argue in their article published in Clio. Women, Gender, History that such ideology was markedly more extreme in Frankist practice than that of prior leaders and took a specific focus on the display of feminine sensuality.