Gentry was formed in 1978, by guitarist Kai Hansen and guitarist/vocalist Piet Sielck, who quickly recruited Ingo Schwichtenberg on drums, and then a short time later Marcus Grosskopf on bass. Songs from this era include "Murderer" (1979), parts of "Heading For Tomorrow" (!) (1980), "Iron Savior" (1980), "Gorgar" (1981), "Metal Invaders" (1981), "Save Us" (1982), and "Victim Of Fate" (1982).

The band changed its name to Second Hell in 1981, and then Iron Fist (Deu) in 1982, recording a demo under that name in 1983.

Helloween officially became Helloween in 1983, when Piet Sielck left and Michael Weikath of "Powerfool" entered (bringing with him, among other things, an early version of "How Many Tears" called "Sea Of Fears" from 1982), and the band changed its name. Helloween was purposely spelled that way, according to Kai Hansen. "Halloween comes but once a year, but you can have Helloween every day." At this point, Kai took over vocals.

At one point, Ralf Scheepers was invited to sing in the band, but he declined the offer. Michael Kiske was found soon thereafter.

Kiske went on to play much softer music after leaving Helloween but has made numerous guest appearances for metal bands including Avantasia, Edguy, Masterplan and Revolution Renaissance.

After a split with Nuclear Blast, Helloween signed a deal with SPV Records in 2004.

Richie Abdel Nabi played live drums in 1993.

Also worth mentioning:
- Piet Sielck - Guitars, Vocals (1978-1983) (Iron Savior, Savage Circus, ex-Iron Fist (Deu), also has worked extensively as a producer/engineer). Was never quite in Helloween, as he was the predecessor of Weiki, but co-wrote many songs that later appeared on the "Helloween" EP and "Walls of Jericho".
- Jørn Ellerbrock - Keyboards, on all releases from "Pink Bubbles go Ape" to "Rabbit don't come easy". Jørn Ellerbrock was also present in most live appearences of Helloween.

Born Dates:
Andreas Deris (18th August 1964 Karlsruhe, Germany)
Michael Weikath (7th August 1962 Hamburg, Germany)
Sascha Gerstner (2nd April 1977 Stuttgart, Germany)
Markus Grosskopf (21st September 1965 Hamburg, Germany)
Daniel Löble (22nd February 1973 Zürich, Switzerland)
Kai Hansen (17th January 1963 Hamburg, Germany)
Roland Grapow (30th August 1959 Hamburg, Germany)
Michael Kiske (24th January 1968 Hamburg, Germany)
Ingo Schwichtenberg (18th May 1965) R.I.P. 8th March 1995
Uli Kusch (11th March 1967 Aachen, Germany)
Mark Cross (2nd August 1965 London, England)
Mikkey Dee (31st October 1963 Gothenburg, Sweden)
Stefan Schwarzmann (11th November 1965, Germany)