Moynihan was born in Boston, Massachusetts to a lawyer father. Moynihan identifies his background as entirely Northern European: Irish, English, Welsh, and German. Moynihan attended Buckingham Browne & Nichols, a private day school in Cambridge, Massachusetts. He became active in experimental music from 1984, forming Blood Axis in 1989 and releasing his first album under the name in 1995.
Moynihan collaborated with Boyd Rice from 1989, and in 1990 the two moved into an apartment in Denver. Like Rice and Thomas Thorn, Moynihan was a member of the Church of Satan at this time. Moynihan appeared as a guest with Rice and James N. Mason on a special episode of Bob Larson's Christian radio talk show titled "Manson Maniacs". During the summer of 1991, Moynihan states that he was visited at his apartment by agents of the United States Secret Service about an alleged plot to assassinate then President of the United States George H. W. Bush. Moynihan agreed to a polygraph test and no charges were filed. Moynihan stated that it was a simple case of intimidation stemming from his correspondence with Charles Manson and visits to Sandra Good. Moynihan stated that he felt that he had been monitored by the Federal Bureau of Investigation since 1984, that they had taken his luggage on an occasion, and that they had once called his father, admitting to him that they had taken a parcel from his mail. Moynihan cited his then-friendship with Peter Sotos as a potential cause.
Differences between Boyd Rice and Michael Moynihan led to an acrimonious split between the two in the mid-1990s, though Rice would later remember their time together fondly and refer positively to Moynihan. After the split, Moynihan disassociated himself with Rice and was no longer involved with the Abraxas Foundation. Moynihan has been a member of the small Asatru collective Wulfing Kindred since 1994.
In 1995, Moynihan released the first full-length album by Blood Axis, The Gospel of Inhumanity and moved from Denver to Portland, Oregon where he became an editor at Feral House, a publishing company owned by Adam Parfrey. After studying language and history at the University of Colorado and Portland State University, Moynihan received his B.A. in German language in 2001.
Moynihan is one of the editors of TYR: Myth – Culture – Tradition and the North American editor of Rûna.
In 1992, Moynihan edited and published a collection of writings by National Socialist Mansonite James N. Mason into a book entitled Siege: The Collected Writings of James Mason.
In 1998, Feral House published the book Lords of Chaos: The Bloody Rise of the Satanic Metal Underground, which Moynihan co-authored with Norwegian journalist Didrik Søderlind. It won the 1998 Firecracker Alternative Press Award.
During this period Moynihan contributed to various magazines and journals, including Seconds and The Scorpion. Among the artists and figures he has interviewed are: power electronics founder Whitehouse; Unleashed; Bathory; In the Nursery; Church of Satan founder Anton LaVey; convicted murderer Charles Manson; Peter Steele of Type O Negative, discussing Social Darwinism; Burzum; George Eric Hawthorne of RAHOWA; Misfits founder Glenn Danzig; Throbbing Gristle and Psychic TV founder Genesis P-Orridge; and Swans founder Michael Gira.
In 2001, Moynihan co-authored The Secret King with Stephen Flowers. 2001 also saw Moynihan editing a reprint of Julius Evola's book Introduction to Magic, originally published in 1929, and in 2002 he edited the first English language translation of Evola's 1953 book Men Among the Ruins (both published by Inner Traditions). In 2005 Moynihan edited and published a collection of essays by British writer John Michell (selected from Michell's contributions to The Oldie) entitled Confessions of a Radical Traditionalist.
Moynihan is best known for his 1998 account of the early Norwegian Black Metal scene. Reviews of Lords of Chaos have been mixed, with several critics praising the book for offering an informative or at least interesting view on a relatively obscure sub-culture, winning the 1998 Firecracker Alternative Press Award. The publication was sometimes criticized for a perceived lack of distance towards its subject matter. This was considered especially alarming to groups and figures that had accused Moynihan of right-wing sympathies, charges which Moynihan has dismissed as inapplicable due to the "intricacies of such subjects".
Tyr: Myth—Culture—Tradition is a journal edited by Moynihan together with Joshua Buckley. The publication is named after Tyr, the Germanic god. The editors state that it "celebrates the traditional myths, culture, and social institutions of pre-Christian, pre-modern Europe." The first issue was published in 2002 under the ULTRA imprint in Atlanta, Georgia.
The editorial preface of Tyr, vol. 1 defines an anti-modern, anti-capitalist ideal of "Radical Traditionalism" encompassing:
- Resacralization of the world versus materialism.
- Natural social hierarchy versus an artificial hierarchy based on wealth.
- The tribal community versus the nation-state.
- Stewardship of the earth versus the "maximization of resources."
- A harmonious relationship between men and women versus the "war between the sexes."
- Handicraft and artisanship versus industrial mass-production.
Influenced by first wave industrial music artists such as SPK and Throbbing Gristle, Moynihan started his first musical project in 1984, a power electronics project named Coup de Grace, for which he produced cassettes, image booklets, essays and performed live. In 1988, at the age of 18, Moynihan published an edition of Friedrich Nietzsche's The Antichrist featuring artwork by Trevor Brown.
According to Moynihan, a cassette from his project Coupe de Grace was received by a group called Club Moral in Belgium, resulting in a positive review in an art and music magazine called Force Mental. This resulted in an invitation for Moynihan to come to Europe, which he accepted, and resulted in a small European tour of Germany and the Netherlands, while he was based in Antwerp, Belgium. Here, he came in contact with Cthulhu Records. Upon returning to Boston in the United States, he was invited to join the experimental music group Sleep Chamber.
While a member of Sleep Chamber, Moynihan met Thomas Thorn. According to Moynihan, a falling out occurred between Thorn and John Zewizz, founder of Sleep Chamber, resulting in Moynihan leaving Sleep Chamber and moving to Belgium, where he lived in a warehouse on invitation by Club Moral. During this time, Moynihan described himself as a skinhead. Living without electricity, a low monthly fee and illegally in Belgium, Moynihan stated it was "worth the risk" but had to install many of his own utilities.
Thorn, who had formed a new, fascistic techno group called Slave State, visited Moynihan in Belgium and the two played in a room beneath the warehouse where Moynihan was staying at this time. After the show, Moynihan became displeased with his illegal status and visited the founders of Cthulhu Records in Germany for a few days. After returning to the US in 1989, Moynihan formed the musical group Blood Axis and no longer produced music under the name Coup de Grace.
Experimental musician Boyd Rice invited Moynihan to go to Japan and collaborate with him on some NON performances there in 1989. Moynihan performed in concert with the various musical groups rotating around Tony Wakeford, Douglas P., and Rose McDowall who were also performing. His performance in Japan with NON was later released as the "Live in Osaka" DVD. That year, an album entitled Music, Martinis, and Misanthropy grew out of these collaborations.
In 1995, Moynihan also released the first full-length album by Blood Axis, The Gospel of Inhumanity and has seen several subsequent re-issues on various labels. It was followed by a second Blood Axis album in 1997 entitled Blot: Sacrifice in Sweden for the Swedish post-industrial music label Cold Meat Industry.
In 2001, Moynihan released a musical collaboration with French artist Les Joyaux De La Princesse entitled Absinthe: La Folie Verte themed around absinthe, a beverage Moynihan has expressed fondness for, and collaborated with Portland natives B'eirth of In Gowan Ring, his partner Annabel Lee and Markus Wolff of Waldteufel for a project dubbed Witch-Hunt. Largely playing traditional acoustic Irish folk music, the group played various local shows in Portland and also, in 2001, performed in Portugal, where the album Witch-Hunt: The Rites of Samhain was released. In 2008, Moynihan appeared on the album "Hoodwinked" by The Lindbergh Baby and an Italian language book entitled Day of Blood was published focusing on the musical group.
Matthias Gardell writes in his 2003 book Gods of the Blood: "Featured in different contexts, Moynihan projects many different faces and has been classified as an "extreme rightist" an "extreme leftist", a Nazi, a fascist, and an anarchist."
Gardell lists Charles Manson, Muammar al-Gaddafi, Mikhail Bakunin, Julius Evola, James Mason and Miguel Serrano as Moynihan's influences.
Investigative journalist Kevin Coogan has linked Moynihan more explicitly with the extreme right but states that Moynihan does not fit into a "conventional definitions of fascism". Coogan has classified Moynihan as an "extreme rightist". Coogan states that Lords of Chaos "itself, however, is not a "fascist" tract in the strict sense" and that "Moynihan [does not] himself fit easily into the more conventional definitions of fascism".
Schobert (1998) considers Moynihan a musical lightweight who profited from association with Rice and successfully managed to style himself as a provocative "cult figure". Examples for such provocative behaviour include a 1994 interview with No Longer a Fanzine (no. 5, p. 8) which led to activist allegations that he was "a major purveyor of Neo-Nazism, occult fascism and international industrial black metal music."
The album The Gospel of Inhumanity (1995) was favorably reviewed by far-right and neo-Nazi publications: the US Nazi skin journal Resistance (no. 6, 38) praised it as a "fascist symphony". The album also brought Moynihan to the attention of the German neo-Nazi scene, a favorable review appearing in Einheit und Kampf. Das revolutionäre Magazin für Nationalisten (no. 18, p. 29, Aufruhr-Verlag, Bremen). As a consequence, Moynihan was identified by anti-fascist activists in the late 1990s. Blood Axis performances attracted protesters, on one occasion in 1998, "about 75" San Francisco protesters mobilized by a flyer denouncing Moynihan as "a fascist and a hatemonger" succeeded in preventing his appearance. Moynihan dismissed activists labeling him a Nazi or a Fascist as misinformed hysterical alarmism.
In 1999, Moynihan was one of several musicians listed by Southern Poverty Law Center's Intelligence Report magazine as examples of black metal music being used to recruit white supremacists. The magazine also excerpted an interview with No Longer a Fanzine, where Moynihan denied the Holocaust but said that he would "prefer it if it were true". The SPLC article was criticized by Decibel Magazine in 2006 which described it as being misleading and being poorly researched. In the Decibel article, Moynihan responded to the SPLC report, saying it was "packed with misinformation and outright errors" and focused "on a few provocative statements selectively culled from interviews done nearly 15 years ago".
German social scientist Christian Dornbusch remarks that Moynihan's work "evokes a mindset which wants to design a future based on völkisch and fascist respectively national socialist thinkers. It's the same goal that the British fascist leader Sir Oswald Mosley rants about for minutes in the sample at the beginning of the live album Blot – Sacrifice in Sweden: »... we are fighting for nothing less than the revolution of the spirit of our people ...«".
Moynihan has repeatedly denied political ties. In response to the various political accusations leveled against him, Moynihan calls the far-right "a bunch of isolated losers" who are "all deluded".
Moynihan is involved in a long-standing collaborative and romantic relationship with musician Annabel Lee, with whom he has fathered a child.