Rainbow was formed by Deep Purple axeman Richie Blackmore in 1975. He was joined by Elf members Ronnie James Dio (vocals) and Mickey Lee Soule (keyboards), Craig Gruber (bass) and Gary Driscoll (drums). The line-up was to change many times over the life of the band; several of the best known British heavy rock musicians spent time in the band.
Elf had been a support band with Purple and, during that time, Blackmore and Dio started to write and work together. Such was the rapport, that Elf was effectively dissolved and Rainbow rose from the ashes. The result was debut album Richie Blackmore's Rainbow, released in 1975.
After that album, Blackmore replaced the entire band except Dio, recruiting Cozy Powell (drums), Jimmy Bain (bass) and Tony Carey (keyboards). Together they released Rising (1976), but, once again, everybody was fired after the album, except Dio and Powell. After the following album Long Live Rock 'n' Roll (1978), Blackmore announced that he planned to move the band into more commercial territory and away from the 'fantasy' themes beloved of Dio. Dio left and Black Sabbath were the next recipients of his vocal talents.
Rainbow's next vocalist was Graham Bonnet and it was at this point that former Deep Purple bassist Roger Glover joined the team for a short while. Down to Earth (1979), the next album, was the origin of two hit singles "All Night Long" and "Since You Been Gone".
The line-up changes continued over the course of the next three successful albums.
By 1984 Blackmore and Glover had decided to reform Deep Purple and, after the live album Finyl Vinyl (1986) Rainbow foundered.
Blackmore reformed Rainbow in 1993 but, after a hugely successful tour and a successful album Stranger in Us All (1995) he put Rainbow on the back burner so that he could focus his attention on Renaissance and medieval music with a band he called Blackmore's Night.
A reunion was mooted in 1997, but the death of Cozy Powell ended that hope and, while rumours of a reunion have abounded, none has surfaced.