The band's name is inspired by the title of Salman Rushdie's first novel. Grimus is the approximate anagram of the word "Simurgh", a gigantic bird from the Persian mythology.

Grimus start off with a self-released 3-song Demo, recorded near the end of 2005, with the track Solitude being the most notable success, after receiving the "Song of the Year 2006" award by City FM Radio, Bucharest.

By 2007, the band is invited to perform for all major festivals in Romania and plays regularly in various pubs all over the country. In October 2007, Grimus are awarded the "Best New Romanian Band" title after winning the National Finals in the Global Battle of the Bands. Thus in December they represent Romania in the GBOB World Finals at the Underworld venue in Camden Town, UK.

In 2008, Grimus are mainly focused on recording and releasing their debut album Panikon, which receives positive reviews from most Romanian music critics and is awarded the "Best Romanian Album of 2008" by www.muzicisifaze.com

The first single Backseat Driver is a radio hit, after 4 weeks Number One in the Top 40 at Guerrilla Radio Station and 5 weeks Number One in the Romtop at City FM Radio Station.