After leaving Vice in 2008 because of creative differences with his partners, Mr. McInnes went on to write a series of books, like “How to Piss in Public,” and articles for right-wing websites, like Taki’s Magazine and VDARE.

Even in his earliest work, Mr. McInnes often took an adolescent pleasure in offending liberals, women, “beta male culture” and transgender people, writing in a voice inflected with a crass, contrarian bigotry that left him just enough room to declare it all a joke.

In 2016, Mr. McInnes founded the first official chapter of the Proud Boys in New York after, he said, he realized that fans of his former television program, “The Gavin McInnes Show,” liked to spend time in his studio, drinking beer with him and telling private jokes.

He has described the group, which has since spread to dozens of cities and to countries, like Australia and Japan, as an ordinary men’s club, like the Shriners or the Elks. It serves as a sort of safe space for him and what he calls his fellow “Western chauvinists.”

In its guise as a fraternal organization, the Proud Boys get together in New York and other cities once a month at beery meet-ups that can draw as many as a few hundred participants. Women are not allowed at the group’s formal gatherings (though they are permitted at the “warm up” sessions, Mr. McInnes has written). As a character-building exercise, the Proud Boys forbid both masturbation and the watching of pornography. The group’s initiation rituals include reciting the names of five breakfast cereals while being slugged by other members.

The monthly meet-ups are largely “social events where people have fun and laugh and drink and share stories about their kids and businesses and stuff like that,” said Pawl Bazile, the editor of Proud Boy magazine. “It’s a celebration of the West, of America and of freedom and liberty.”

But in the last two years, members of the group have also had a second preoccupation, taking part in a string of violent street fights with their anti-fascist rivals in cities like Berkeley, Los Angeles and Portland, Ore.