In 1960, LIFE magazine assigned Eve Arnold, who died in January 2012 at the age of 99, to document the days and nights of Malcolm X, the controversial and intensely charismatic public face of the Nation of Islam.

At the very first NOI rally she attended, at the Uline Arena in Washington, D.C., Arnold photographed George Lincoln Rockwell, head of the American Nazi Party, who had forged an alliance with the Nation of Islam (and who, like Malcolm X, would be assassinated before the decade was over). Arnold — born into a Russian-Jewish family in Philadelphia in 1912 — wrote later that, as she raised her camera to photograph Rockwell and his brownshirt-clad henchmen, he hissed at her, “I’ll make a bar of soap out of you.”