Formed in 1992, Kris Kristiansen & Michael Devin were drawn to the electronic invasion on the British music scene. Influenced by the house music scene and artists such as Adamski, N-Joi, Prodigy, Future Sound Of London, Hardfloor and everything else that was happening in the club scene whether it was acid house, house, techno, hardhouse or hardcore. Their first release, "My Guitar Hertz", on Higher State records was a collaboration with Cream DJ Paul Bleasdale and resulted in a Party house tune, with a more commercial sound suited for the likes of Cream's back room. The trio was asked to remix "Deliver Me" for the Cotton Club which rode on the success of the Cotton Clubs previous releases.

In 1994, the duo sent a demo tape to Hard Hands, the label created by Leftfield's Paul Daley and Neil Barnes. This led to a Hard Hands release under the name of "Sentinel", a 3-track EP titled "Hurricane". This included the track "Transistor Rhythm" which received heavy airplay by Annie Nightingale on Radio 1.

Another collaboration followed in 1995, this time with Andrew Weatherall and Jagz Cooner of Sabres Of Paradise (along with Bleasdale again), this produced the heavy underground sound of "Crash" under the name of Cymbol on Concrete Recordings. This caught the attention of DJ's like Justin Robertson and Annie Nightingale.

In 1996, Kris worked with resident Voodoo Club DJ Mike Williams to release a string of E.P's on Charlie Halls label MC Projects, this time under the guise of Multiplex.

Since 1996 and the ever-changing electronic scene, Devin & Kristiansen's sound has developed into the heavy electro sound of Electric Voodoo. Released on their own label Fine-As-Wine records, the initial release was the first of many Electric Voodoo produced tracks.

In 2000, the duo released their first track under name of 21st Sentry. The track "Hitman" became the opening track on the compilation, 'Corrosive Breaks' released on cd by Atomic records.

As of 2006, the duo record under the name of 21st Sentry and Electric Voodoo.