Larry Flynt, a ninth-grade dropout who built a $400 million empire of raunchy publications, strip clubs and “adult” shops around his sexually explicit magazine Hustler, and spent decades battling obscenity and libel charges as a self-promoting champion of freedom of the press, died on Wednesday at his home in Los Angeles. He was 78.

The cause was heart failure, said his brother, Jimmy Flynt.

To a nation in the throes of a sexual revolution in the 1970s, Mr. Flynt — defiant, outrageous, relentless — was at the nexus of a cultural and legal war in America: an unpopular hero to civil libertarians, the Devil incarnate to an unlikely alliance of feminists and morality preachers, a conundrum to judges and juries, and a purveyor of guilty secrets to legions of men slinking off from porn shops or the mailbox with brown paper parcels.

Hustler’s June 1978 cover caught the enigmas of a magazine that was at once salacious, satirical, perverse, decadent, gleefully immoral and hypocritical. It portrayed a woman upside down and half gone into a meat grinder, with a plate of hamburger below. A “seal of approval” noted: “Prime. Last All Meat Issue. Grade ‘A’ Pink.” A caption quoted Mr. Flynt, “We will no longer hang women up like pieces of meat.”

But, of course, Hustler was not serious. Starting with its first issue, in July 1974, and continuing nonstop for four decades, it displayed glossy, full-color photos of female genitalia, pictured naked women in demeaning poses and often depicted group sex and sex-toy fetishes.

Hustler articles offered “Larry Flynt on Sex in the White House,” “Coverbabe: New Slut in Town” and “Dirty Bedfellows: Explicit Photos & Sordid Tales From a Real Washington Intern.” But it was not all sex; there were also articles like “The Politics of Torture,” “Grenada Invasion: The True Story Behind Reagan’s ‘Facts’ ” and “Shocking New Facts in J.F.K. Assassination Coverup.”

Mr. Flynt’s most significant legal victory came in a long fight against the Rev. Jerry Falwell, the television evangelist and founder of the Moral Majority, who sued for $45 million for libel and emotional distress in 1983 after Hustler published a parody in which he reminisced about a sexual encounter with his mother in an outhouse.

A jury rejected the libel charge, saying the parody was obviously not factual, but awarded Mr. Falwell $200,000 for emotional distress. In 1988, the Supreme Court unanimously threw out the damages, calling the parody constitutionally protected political satire.

Mr. Flynt hailed the decision as the most important First Amendment victory since the obscenity ban on James Joyce’s “Ulysses” was overturned in the 1930s.