Though failing to break through early in their tenure, the band has received acclaim for their albums Undoing Ruin, Deliver Us, and The Eternal Return.

[3] Darkest Hour played their first show on September 23, 1995,[4] and initially consisted of vocalist John Henry, guitarist Mike Schleibaum, drummer Matt Maben, and bassist Raul Mayorga.

In 1996, Darkest Hour cut a single titled "Paths of Despair" for East Coast Empire Records' The Harder They Come compilation.

In 1999, Darkest Hour released another EP titled The Prophecy Fulfilled on another label called Art Monk Construction.

The addition of lead guitarist Fred Ziomek, bassist Billups Allen and drummer Ryan Parrish saw the band release their first full-length LP The Mark of the Judas in 2000, on the now-defunct M.I.A.

On March 7, 2007, Victory Records issued a press statement confirming the title of the album was Deliver Us; it was released on July 10.

In March 2009, Darkest Hour began to record the new album, The Eternal Return, just before co-headlining (along with Bleeding Through) the Thrash and Burn European Tour 2009 in April and May.

[12] The new album will be produced by Soilwork guitarist Peter Wichers, who helped pioneer Swedish melodic death metal and was a major influence on Darkest Hour.

"[13] In a new Metal Injection interview, Darkest Hour members Mike Schleibaum and Ryan Parrish revealed that the new record would be titled The Human Romance, and it was officially released on February 22, 2011.

On June 6, 2012, Darkest Hour announced that bassist Paul Burnette would be amicably leaving the band to join Iron Reagan.

No longer contractually obligated with any record label, in early 2016 Darkest Hour launched an IndieGoGo crowdfunding campaign to help pay for their upcoming ninth studio album as well as their first ever full-length live DVD, Live at the Black Cat 2015, which was a special show where they celebrated the tenth anniversary of Undoing Ruin.

Commenting on the choice of producer, Schleibaum said, "We want bring the energetic, raw, emotion we exude live to tape this time.

Also, it doesn't hurt that we completely respect and trust him as both a friend and musician, meaning we feel this monumental task of bringing another Darkest Hour album to life will rest well in his hands.

[24] On September 21, 2021, Darkest Hour announced that Nico Santora (formerly of Fallujah, Suicidal Tendencies, The Faceless and Lillake) would be touring with them on lead guitar.

Other influences include: Dark Tranquillity,[28] Minor Threat, Earth Crisis, Bad Brains, Black Flag, Van Halen, Government Issue, Scream, Shadows Fall, Entombed, Dismember, Sacrilege, The Crown, Ozzy Osbourne, Metallica, Megadeth, Slayer, Anthrax, Iron Maiden, Dream Theater, Carcass, Arch Enemy,[29] Sick of it All, Dead Kennedys, Soilwork,[30] Danzig,[31] Venom, Exodus, Discharge, Cro-Mags, Integrity,[32] Edge of Sanity, Mayhem, Emperor, Ulver,[33] Testament, Death Angel, Pantera, and Cannibal Corpse.

[34] Darkest Hour's main guitar influences are: Zakk Wylde, Dimebag Darrell, James Hetfield, Dave Mustaine, and Scott Ian.