Zionist lore says Herzl became a Zionist after witnessing the Dreyfus Affair and hearing the crowd chant "Kill the Jews." But historical evidence shows that's not what made Herzl into a Zionist, (and also the crowd did not chant "Death to the Jews").

Links to Sources Cited

• The Jews' state, Theodor Herzl; translated, and with an introduction by Henk Overberg
• The Diaries of Theodor Herzl, Edited by Marvin Lowenthal
• Herzl's Vision: Theodor Herzl and the Foundation of the Jewish State by Shlomo Avineri
• Cohn, Henry J. “Theodor Herzl’s Conversion to Zionism.” Jewish Social Studies 32, no. 2 (1970): 101–10. 

Photo of Alfred Dreyfus by Aron Gerschel, Public domain, via Wikimedia Commons