Blind Guardian formed in 1984 as a German Celtic Metal band in Krefeld, Germany, by Hansi Kürsch (vocals, bass) and Andre Olbrich (guitar) under the name Lucifer's Heritage. The band first released two demos in 1985 and 1986, despite undergoing chaotic lineup changes: Markus Dörk (guitar) and Thomen Stauch (drums) were replaced by Christof Theißen and Hans-Peter Frey, respectively. Finally, in 1987, Marcus Siepen joined and Thomen came back to form the lineup which would stay consistent for the next 18 years.

After Lucifer's Heritage signed a contract with No Remorse Records, the band changed their name to Blind Guardian to avoid any speculations about Satanism (in a bio it was stated that they also wanted to distance themselves from the black metal movement, as their demos were placed in with black metal albums at local record shops). They released their debut album Battalions of Fear in 1988, which was essentially a speed metal album heavily influenced by Helloween. These two German bands had close ties, and Helloween founder Kai Hansen made a guest appearance on Blind Guardian's second LP, Follow the Blind (1989), where the band revealed some thrash metal influence. Their third LP, Tales from the Twilight World (1990), had a much more melodic and "epic" feeling, with usage of choir and classical music influence.

Blind Guardian signed with Virgin Records in 1991, and released their fourth studio album Somewhere Far Beyond in 1992 the live album Tokyo Tales in 1993. Flemming Rasmussen, former Metallica producer, began working with the band in 1994, producing their fifth studio album Imaginations from the Other Side, released in 1995, and The Forgotten Tales, an album that contained half covers and half original work, released in 1996.

In 1998, Blind Guardian released their epic album Nightfall in Middle-Earth. "Complete with anthemic choruses, spoken word story lines, and plenty of bombastic power metal punctuating every dramatic turn", says Allmusic's Vincent Jeffries, "Nightfall in Middle-Earth is perhaps Blind Guardian's most triumphant". A concept album based on J. R. R. Tolkien's The Silmarillion, Blind Guardian's music demonstrated some folk rock influence, but also featured heavy use of Queen-style layered backing vocals. Since "Nightfall", bass guitar has been played by sessional member Oliver Holzwarth, and Hansi has been able to devote all his attention to singing. "Nightfall" was also the last Blind Guardian album produced by Rasmussen.

A Night at the Opera, named after the Queen album, was released four years later. On this album, the band's sound lacked almost all influence of their original speed metal. Power and progressive metal abound, with over the top orchestral backing and a consistent vocal and guitar layering throughout. Though not a true concept album, many of the lyrics dealt with the common themes of religion and relations between human and divine powers. It was followed by a live album in 2003 and a DVD, Imaginations Through the Looking Glass (2004), which was the last recorded Blind Guardian material to feature Thomen Stauch on drums. He left the band due to musical differences and was replaced by Frederik Ehmke. The first album with Ehmke was A Twist in the Myth, which came out in 2006.

Blind Guardian recently participated in the soundtrack for the In the Name of the King: a Dungeon Siege Tale fantasy movie,(Uwe Boll) which came out in 2008. The band also recorded a theme song for Sacred 2 Fallen Angel RPG video game, the prequel to Sacred. According to recent interviews, the song, titled "Sacred", will not be released until their next album as a bonus track. Songwriting for their next album has started and at the same time the band is working with the Orchestral Project. It will be decided at a later date whether they will release a new album or the Orchestral Project first. Regardless, there won't be a new album released before 2010. The orchestral project may be postponed however; in a recent interview at Bloodstock 2009, the band revealed that their new material is of a similar style to Nightfall in Middle Earth.

Blind Guardian's first two albums, Battalions of Fear and Follow the Blind, were more in the style of speed metal than their following works. Beginning with their third album Tales from the Twilight World, Blind Guardian gradually began to write more complicated compositions focusing less on speed. As of their sixth album, Nightfall in Middle Earth, Hansi stopped playing bass to focus on singing. At this point the band began to incorporate large amounts of orchestral arrangements, and utilized the technique of overdubbing, heavily influenced by the English rock band Queen.

Blind Guardian's music features the staccato guitars and double bass drumming characteristic of power metal, as well as the use of overdubs to create a dense, "epic" sound. This technique, especially notable in the guitar and vocal tracks, creates the impression of a vast army of musicians playing in unison and singing in harmony. This proved significant on all albums after the first two but most particularly on A Night at the Opera which was highly regarded among fans.

Along with Jon Schaffer, the leader and founder of Iced Earth, Kürsch is a member of Demons & Wizards, where he is the lead singer.

Blind Guardian have been working on and off for eight years on an orchestral project writing music about The Lord of the Rings (negotiations failed to be included on the famous The Lord of the Rings film trilogy as the soundtrack, because the band wanted to concentrate on their next album). Although it will not be a power metal album, it will be published under the name of Blind Guardian because it matches the theme of the band's lyrics, according to Hansi and André.