http://www.publiceye.org/tooclose/protocol.html
Most researchers believe the Protocols grew out of propaganda intrigues of the secret police of Czarist Russia in the late 1800's. The main Russian print source for the Protocols first appeared as an appendix in The Big in the Small, and Antichrist as a Near Political Possibility; Notes of an Orthodox Person by Sergei A. Nilus, published in 1905 but republished to wider audiences in 1911 and 1917. Another (but far more obscure) publication is by G. Butmi de Katzman, Enemies of the Human Race, published in 1906. The versions are not identical but very similar, and Nilus' Protocols are more often the source for versions translated and printed internationally. The Nilus version contains 24 protocols as opposed to Butmi's 27.
The Protocols themselves are plagiarized from and inspired by earlier works that allege conspiracies, especially a satiric French work Dialogue in Hell between Machiavelli and Montesquieu by Maurice Joly published in 1865; and a German novel Biarritz by Hermann Goedsche published in 1868. Equally dubious documents purporting to reveal secret conspiracies have circulated for centuries.