After Ms. Nie put up her poster on May 25, 1966, Peking University erupted in debate. Officials and students were unsure how far attacks could go. The campus was soon awash in rival posters supporting or rejecting the accusations that Mr. Lu, the university’s party secretary, and two other officials were resisting Mao’s orders.
A few days later, Kang Sheng, a powerful security official, reported to Mao about the poster. Mao immediately grasped it as kindling for his Cultural Revolution. He ordered that the poster be reprinted and circulated. He later praised it as the “first Marxist-Leninist big-character poster in the country.”
Ms. Nie leapt to political stardom. She joined Mao when he reviewed a sea of Red Guards in Tiananmen Square. Pictures from that time show Mao and Ms. Nie in cheerful conversation.
But Ms. Nie later said that she had developed misgivings about the Cultural Revolution.
“I didn’t know we were heading toward disaster,” she told The New York Times in 2006. “Once I understood,” she added, referring to the party’s orders, “I stopped following them.”
Even so, she remained a prominent Red Guard leader, trusted by Jiang Qing, Mao’s wife, who was among the most fervent radicals.
Ms. Nie fell out of favor after Ms. Jiang accused her of disobedience in 1968. Mao died in 1976, and a few years later Ms. Nie was arrested and detained. In 1983 a court in Beijing sentenced her to 17 years in prison on charges of persecuting and vilifying people, including party leaders. She was released on medical parole in 1984.
Ms. Nie was married twice; both husbands are dead, her son Mr. Yu said. In addition to him, survivors include another son and a daughter.
“I’ve been described as a counterrevolutionary careerist and schemer, an unforgivably wicked madwoman,” Ms. Nie wrote in her memoirs, which grew to almost a thousand pages when reprinted in 2017. “I tell you readers: Thanks be, I’m still alive, and still fighting!”