At his Lake Brantley High School talent show, guitarist Matt Heafy performed cover versions of Metallica's "No Leaf Clover" and "Self Esteem" by The Offspring. Vocalist Brad Lewter noticed Heafy and asked him to try out for his band. The pair went over to drummer Travis Smith's house where they played Metallica's "For Whom the Bell Tolls". Impressed with Heafy's performance, they accepted him into the band known as Trivium. After several shows at bars and local clubs, Lewter quit the band and Heafy took over his position as vocalist. In early 2003, Trivium went into the recording studio to record its first high-quality demo disc. A copy of the demo was heard by German label Lifeforce, who signed Trivium. The band entered a studio to record its debut album, Ember to Inferno.

As time went on, Corey Beaulieu joined. In 2004, Paolo Gregoletto joined as the band's bassist to replace Brent Young, before a tour with Machine Head. The album Ember to Inferno managed to garner the interest of Roadrunner Records representatives, who later signed Trivium to a record deal. They then began writing songs for their major label debut.

In 2004, Trivium recorded its second album, Ascendancy, in Audiohammer Studios and Morrisound Recording in Florida. Produced by Heafy and Jason Suecof, the album was released in March 2005. The album debuted at #151 on the Billboard 200 and at #4 on the Top Heatseekers chart. Allmusic reviewer Johnny Loftus stated on Ascendancy, Trivium are a "ridiculously tight quartet, unleashing thrilling dual guitar passages and pummeling kick drum gallops as surely as they do melodic breaks and vicious throat screeds" and Rod Smith of Decibel magazine praised "Smith's impeccably articulated beats, bassist Paolo Gregoletto's contained thunder, and, especially, Heafy and guitarist Corey Beaulieu's liquid twin leads." The album was also recognized as the "Album of the Year" by Kerrang! magazine. Singles and music videos were released for "Like Light to the Flies", "Pull Harder on the Strings of Your Martyr", "A Gunshot to the Head of Trepidation", and "Dying in Your Arms". The videos for these songs gained rotation on MTV2's Headbangers Ball and Pull Harder on The Strings of Your Martyr has become one of their most well known songs and has become the song that they usually close their set with. In support of the album, Trivium played on numerous tours with well known artists. The band opened for Killswitch Engage, Iced Earth, Fear Factory, and Machine Head, who were one of Heafy's largest influences. Trivium played at Road Rage 2005, Ozzfest, and made an appearance at the Download Festival. Ascendancy was re-released in 2006 with four bonus tracks and a DVD containing all of the band's music videos and live footage.

In April 2006, after a headlining tour featuring Mendeed and God Forbid as openers, Trivium entered the studio with Suecof and Heafy producing again. The band played the Download Festival again, this time on the main stage with Korn and Metallica. Trivium released The Crusade in October 2006. Debuting at number 25 on the Billboard 200, the album sold over 32,000 copies in its first week of sales. The album was a critical success, with Andy Greene of Rolling Stone claiming "Nothing mars a good metal record like so-called harsh vocals" and Don Kaye of Blabbermouth.net stating The Crusade "is one of the best metal releases of 2006 and quite possibly the heavy music album of the year." On The Crusade, Heafy's vocals changed from a metalcore scream that was heard on Ascendancy, to more singing on this album.The band supported the album by touring with Iron Maiden and Metallica, appearing on the Black Crusade tour with Machine Head, Arch Enemy, DragonForce and Shadows Fall, as well as headlining a European tour with supporting acts Annihilator and Sanctity and acquiring an opening slot on the Family Values Tour with Korn. Trivium was named the best live band of 2006 at the Metal Hammer Golden God Awards.

In September 2008, Trivium released their fourth full-length album, Shogun. The album sold 24,000 copies in the United States in its first week of release, and debut at number 23 on the Billboard 200 chart as well as Number 1 in the UK Rock Album Charts.