Allegaeon was formed in 2007. They initially played small shows at bars and houses in and around
Fort Collins. In August 2008, they independently released a self-titled EP. In January 2010, Allegaeon entered the studio to record their debut album,
Fragments of Form and Function. The album was released on July 20, 2010, through Metal Blade. In December 2011, Allegaeon went to
Lambesis Studios in San Diego, California, to record their second full-length album,
Formshifter.
Formshifter was released on May 8, 2012, through Metal Blade. In 2013, founding guitarist Ryan Glisan collaborated on a project with
Tim Lambesis and left the band shortly thereafter. He was replaced by Michael Stancel. Their third full-length album, titled
Elements of the Infinite, was released on June 24, 2014, through
Metal Blade. The album received significant praise, with Gregory Heaney of
AllMusic calling it a "creative breakthrough" and commending "the dazzling guitar work" and "epic orchestral flourishes." In 2015, original vocalist Ezra Haynes departed Allegaeon without citing a specific reason, though it was made clear that his departure was not due to internal band issues. Riley McShane was immediately selected to take over as vocalist and received a positive reaction from fans. In September 2016, Allegaeon released
Proponent for Sentience, the first album featuring Riley, which was considered their finest work to date. The album received widespread acclaim and was critically noted for its significance in modern metal. It features guest vocals by
Björn Strid of
Soilwork and guitar work by Benjamin Ellis of
Scar Symmetry. In October 2016, longtime bass player Corey Archuleta announced he would be leaving the band at the end of the year to focus on his law career. During this time, the band also stated that they had incurred a large amount of debt and were unsure how much longer they could continue. Because of this financial stress, the band launched a fan club through the
Patreon platform and have since focused on continuing to tour and write their next album. Also during 2016, Allegaeon shot studio play-through videos for the songs "Gray Matter Mechanics" and their cover of the
Rush song "Subdivisions," as well as an official video in California for the song "Of Mind and Matrix." The band released a cover of
Rush's song "Animate" as a single on January 5, 2018; the cover was recorded during the
Proponent for Sentience sessions. Allegaeon embarked on their first European tour later that year as a supporting act for
Ne Obliviscaris. In January 2019, Allegaeon announced a release date for their new album,
Apoptosis, and released a music video for the single "Stellar Tidal Disruption."
Apoptosis was released on April 19, 2019, through Metal Blade. On April 3, 2020, the band released a cover of the 1971 song "
Roundabout" by British
progressive rock band
Yes. On October 27, 2021, they announced their new album
Damnum with the release of its first single, "Into Embers." The album was released on February 25, 2022.
Damnum was well received by critics and was named among the top 50 best rock and metal albums of 2022 by
Loudwire. On August 24, 2022, vocalist Riley McShane announced his departure from the band. On September 13, the band recruited original vocalist Ezra Haynes to perform with them on their upcoming European tour. On October 18, 2023, the band released a new single, "Inhumation," and announced that Ezra had formally rejoined the band on a permanent basis. On March 27, 2024, the band released a second single, "Iridescent," accompanied by a music video the band's label described as "absolutely unhinged." A month later, the band embarked on the "Cancer Culture Over North America Tour 2024" alongside
Decapitated,
Septicflesh, and
Kataklysm. == Musical style and lyrical themes ==