One important step is the release of the "Elders of Zion" books. They are from the start of the 20th century, probably released by the Russian Secret Service (Okhrana) with government blessing. It isn't entirely clear as far as I'm aware.

The book purports the classic Jewish World conspiracy and gained at first a lot of traction in Russia, and later on in the rest of the world. The government hoped to get a scapegoat out of furthering the already high antisemitism in the Russian Empire. After the Revolution of 1905 in Russia the country had civil strife up to the end of the Russian Revolution. The Tsar and its government was clinging to everything they could. By saying that the Jews are behind the revolution and everything wrong they wanted to push people away from revolutionary politics.

"The Elders of Zion" then was also highly touted by the Nazis, and later on by Islamic antisemitism in the Arab world and Iran. It is proven to be a complete hoax (unsurprisingly) but that doesn't diminish its role as antisemitic agitation material.

"The Elders of Zion" also marks one of the points that lead from Antijudaism (resentment of Jews on religious grounds) to Antisemitism (resentment of Jews on racial grounds).

Tldr: "The Elders of Zion" is a huge step in establishing the conspiracy theory that "Jews control the World" and is widely circulated until today, even though it is a hoax.