Arcturus was founded originally as a side project for members of various brutal Norweigen black metal bands such as Ulver, Emperor and the notorious Mayhem. Their first release was a 7" single put out in 1991, entitled My Angel, which created a significant underground buzz in the burgeoning Scandinavian metal scene. By 1993's mini album, Constellation, Emperor's Samoth and Ulver's Garm joined founding member Hellhammer (of Mayhem) to establish the band as a real "supergroup" of sorts. Again, this album continued underground fervor, and scored the band a record deal with Century Media. Both of these recordings are exceedingly rare and I haven't heard them, so comparing them to their later stuff is somewhat beyond my scope.
Their first proper release surfaced in 1995 in the way of Aspera Hiems Sinfonia, albeit without Samoth, who was serving time for burning down a small wooden church in rural Norway. However, it was by this point clear that this was a good deal different than your run of the mill black metal bombast. The creepy keyboard melodies, lurching atmospheres and down tempo rhythms provided a more symphonic approach while remaining squarely in the black metal realm. Despite the minor innovations of this album, nothing would prepare metaldom for what would come next. 1997's La Masquerade Infernale is a progressive metal maelstrom that jars loose any possible genre linkage, veering uncontrollably from operatic fervor, swirling keyboards and dramatic, utterly unconventional song structures. Conceptually structures upon anti-Christian and/or Satanic themes, yet literary and profound in its delivery, the album is definitely a work of paradox, subtlety and blinding brilliance. Today, its still an album that still stands without imitation or equal, possibly one of the finest, and unequivocally unique, metal-related albums ever released. Apparently they may have sold their souls to Satan in exchange for the moment of collective brilliance, as little has been heard out of the Arcturus camp in a few years, aside from a "remix" album entitled Disguised Masters, which met with a tepid response at best. - Greg Northrup [October 2001]
Source: http://progweed.echoechoplus.com/reviews/arcturus/arcturus-band.html