Perhaps the most influential anti-Semitic text in 19th-century Russia was The Book of the Kahal—a precursor to, and major influence on, the Protocols of the Elders of Zion. Its author, Yakov Brafman (1825-1879), was a Jewish convert to Christianity. And he was not the only Russian Jewish convert to use his status to defame his people before an all-too-credulous Russian audience. In fact, the tsar’s secret police kept careful lists of converts who could serve as informers. Among them was Dmitry Ivanovich (né Moshe Itzkovich) Blank, who has the added distinction of being the great-grandfather of Vladimir Lenin. Hadassah Assouline writes:
We know of at least two episodes in which Moshe Blank . . . quarreled with a fellow townsman and members of the community of Starokonsantinov [now in western Ukraine]. In 1809, after a string of earlier disagreements, the Jewish community accused him of setting fire to the town. A trial acquitted Blank, but he left the community and moved to [the nearby city of] Zhitomir, where he continued his retaliation against members of his former community in a letter of complaint that he sent to Tsar Alexander I. This letter, which predates the one below, never reached the tsar but remained with the local authorities in Zhitomir.
Blank also became embroiled in disputes with the local Jews of Zhitomir and following legal proceedings he lost most of his vast property, including a local brick factory. The episode stretched from 1838 to 1844, and immediately afterward Blank converted. . . .
Unlike other letters from informants in the [secret-police] files, Blank’s does not inform on a particular person or on members or leaders of a particular community, but on the Jews of Russia in general, and his missive had consequences for Russian Jewry for years to come. . . .
Two days after the head of the [secret police read Blank’s 1845 letter to Tsar Nicholas I describing systemic Jewish perfidy], he presented the tsar with a report about the letter. . . . In the report, the head of the department noted all of Blank’s accusations against the Jews and suggested adopting a series of measures in the spirit of Blank’s letter. . . . In August 1846, Blank wrote another document, again in Yiddish, “about various methods of converting the Jews.” This document was sent to the Ministry of the Interior, which passed it on, by order of the tsar, to the Committee for Jewish Affairs. . . .
Read more on The Librarians: https://blog.nli.org.il/en/lenins-great-grandfather