"The only statement I care to make about the Protocols is that they fit in with what is going on. They are sixteen years old, and they have fitted the world situation up to this time. They fit it now." - Henry Ford, 2-17-1921, whose newspaper, the Dearborn Independent, cited the Protocols as evidence of an alleged Jewish threat until at least 1927
"To what extent the whole existence of this people is based on a continuous lie is shown incomparably by the Protocols of the Wise Men of Zion...." --Adolph Hitler, Mein Kampf
The Protocols of the Elders of Zion is a forgery made in Russia for the Okhrana (secret police), which blames the Jews for the country's ills. It was first privately printed in 1897 and was made public in 1905. It is copied from a nineteenth century novel by Hermann Goedsche (Biarritz, 1868) and claims that a secret Jewish cabal is plotting to take over the world.
The basic story was composed by Goedsche, a German novelist and anti-Semite who used the pseudonym of Sir John Retcliffe. Goedsche stole the main story from another writer, Maurice Joly, whose Dialogues in Hell Between Machiavelli and Montesquieu (1864) involved a Hellish plot aimed at opposing Napoleon III. Goedsche's original contribution consists mainly of introducing Jews to do the plotting to take over the world.
The Russians used big chunks of a Russian translation of Goedsche's novel, published it separately as the Protocols, and claimed they were authentic. Their purpose was political: to strengthen the czar Nicholas II's position by exposing his opponents as allies with those who were part of a massive conspiracy to take over the world. Thus, the Protocols are a forgery of a plagiarized fiction.
The Protocols were exposed as a forgery by Lucien Wolf in The Jewish Bogey and the Forged Protocols of the Learned Elders of Zion (London: Press Committee of the Jewish Board of Deputies, 1920). In 1921, Philip Graves, a correspondent for the London Times, publicized the forgery. Herman Bernstein in The Truth About "The Protocols of Zion: A Complete Exposure (1935) also tried and failed to convince the world of the forgery.
The Protocols were published in 1920 in a Michigan newspaper started by Henry Ford mainly to attack Jews and Communists. Even after they were exposed as a forgery, Ford's paper continued to cite the document. Adolf Hitler later used the Protocols to help justify his attempt to exterminate Jews during World War II.
The Protocols hoax continues to fool people and is still cited by certain individuals and groups as the cause of all their woes.
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See also here, here and here.