June 2000, in the Swedish town of Helsingborg, members of local black metal acts Abusus Ad Mortem and The Darksend teamed up to form a new band. After the demise of The Darksend in 1999, Tony Richter (vocals) knew that if he should be in another band, he wanted to go back to his roots and return to death metal. As Johan Lindberg (guitars) and Rafael Andersson (drums) still hoped that Abusus Ad Mortem would get a solid line-up together, they saw no reason to be in yet another black metal band and agreed to make the new band a death metal band. Shortly afterwards, the band picked the name 9th Plague for their new musical abomination. In August, former The Darksend guitar player Stefan Stigert was added to the line-up.In
In December 2000, the band had its first recording session. A rushed endeavour as they were eager to get their name known in the underground. The song, "Demonic conjuration" later appeared on the VOD Records compilation "Voices of death part IV: the metal crusade". It was actually so horrible that it should never have been released! The foursome spent most of 2001 trying to find their style and writing material. In November, they made an attempt at recording their first demo. This however failed due to studio equipment malfunctioning. As offers to play some shows appeared, it was decided to put the demo on hold and instead find a bass player and do the shows. It was not until June 2002 that one was found when Kristofer Örstadius joined.
In December 2002, the first demo was finally recorded. It was entitled "Spreading The Satanic Gospel" and exceeded all the band's expectations. It earned them a lot of positive reviews in the underground press and even label offers were made. The purpose of the demo was however not to score a record deal, but to make the name of 9th Plague known in the death metal underground. The time was not right for an album as underground credibility had to be established first and thus the offers were turned down. The demo served its purpose and also managed to get the band banned from the local live circuit due to its title. During the following months, Stefan Stigert gradually lost interest in the band. Having recently become a father, his time was now limited and he did not feel comfortable with everybody calling the band "old school" as he wanted to do something new and fresh.
In June 2003, Stigert left the band on good terms and it was immediately decided that Kristofer Örstadius would switch to guitar. He was a guitar player to begin with, and in all honesty, probably the best of the three. As a result of Stigert's departure, there followed a period of confusion as the song writing team now had changed. The second demo, "Age Of Satanic Enlightenment" (April 2004) was somewhat plagued by this. It also had very lame vocals, which was the result of everybody praising the band as old school. Richter decided to go for an even more old school approach but this turned out to be a very bad idea. Add to this an unsatisfactory production and the end result was not very good. Still it earned the band more label offers, but again they were turned down as the band felt it would be wrong for an album to follow a lousy demo.
In August 2004, bass player Tobbe Hellman was added to the line-up. This however did not work out as well as the band had hoped and in June 2005 he was dismissed. Tired of never finding a decent bass player, it was decided that the band would remain a four-piece with Lindberg switching to bass. The band worked really hard on new material and August 2006 saw the release of the first decent demo, "Triumph Of Diabolism". The intention this time was to secure a record deal. Four days after its release, negotiations with Butchered Records began. Other deals were offered, but Butchered Records seemed the most appropriate label for 9th Plague to work with and this was finally made official in January 2007. The first result of this cooperation is the album "Apocatastasis Reversed". An album that include re-recordings and (in some cases) new versions of six demo tracks as well as six never before recorded, new songs.
Source : www.9thplague.com/biography.html