Horrendous was conceived in the womb of early 2009. With a fascination and utter obsession with the old school, the band emerged from a desolate scene, weaving webs of raunchy riffs through the rehearsal space air.

A demo entitled Sweet Blasphemies was written by the spring of 2009, and recorded in the summer. Copies of the demo were sold on CD-R through the band's myspace page. In mid-2010, Horrendous signed on with Skeleton Plague Records and Dark Descent Records, who co-released Sweet Blasphemies on cassette tape in June. The first pressing of this tape was limited to 200 copies, and was sold out in a couple of months. In March 2011, a second pressing of the Sweet Blasphemies demo was released.

Horrendous have released two studio albums since. The Chills, which saw the light of day in Januars 2012 and Ecdysis, released in October 2014.