The band originally formed in 1966 as Pesky Gee! with Kay Garrett (lead vocals), Kip Trevor (lead vocals, guitar and harmonica), Chris Dredge (guitar), Bob Bond (bass guitar), Clive Box (drums and piano), Jess "Zoot" Taylor (organ), Clive Jones (saxophone and flute). Jim Gannon (guitar, vocals and vibes), replaced Dredge in Spring 1969. The band split in September 1969.
The band released one album for Pye Records as Pesky Gee!, 1969's Exclamation Mark, before Garrett left the band. The remaining band members continued on as Black Widow and released their debut album Sacrifice in 1970. Perhaps better known than their music was the band's use of occult references in their music and their live performances, which were made more controversial with the mock sacrifice of a nude woman. These acts at time were very shocking but now a common use in the underground music scene, black metal. The band attracted further controversy by consulting infamous witch Alex Sanders for advice.
Controversy aside, Sacrifice reached #32 on the UK Albums Chart. The band also performed at the Whitsun Festival at Plumpton, UK, and at The Isle of Wight Festival in 1970. By 1971, the band had moved away from its darker occult imagery in an effort to gain a wider audience, which was unsuccessful. Having replaced Bond and Box with Geoff Griffith and Romeo Challenger, Black Widow released the self-titled Black Widow album in 1971 and Black Widow III in 1972 (by which time Gannon had left, replaced by John Culley) to general disinterest before being dropped by CBS Records. The band recorded an album, Black Widow IV, later in 1972 without a recording contract. It was not released then due to the band breaking up, shortly after replacing lead vocalist Kip Trevor, with another singer known as Rick "E" (born Frank Karuba; formerly of 'Plum Nelly').
The album was finally released in 1997 on the Mystic Records label. In 1999 the original recordings of their debut album, made before Garrett left the band, were released as Return to the Sabbat. In 2000 Black Widow Records (an Italian label) released King of the Witches: Black Widow Tribute featuring bands such as Death SS and Church of Misery as well as tracks featuring original members Kip Trevor and Clive Jones. In 2003 Sanctuary Records released an Anthology 2xCD.
In 2007 Mystic Records released an unreleased concert film Demons Of The Night Gather To See Black Widow - Live as a DVD. The film included Black Widow's entire Sacrifice album show from 1970. The interest towards Black Widow has been growing and because of that Clive Jones and Geoff Griffith have been working on new Black Widow music. Paolo "Apollo" Negri from an Italian hard rock band Wicked Minds has agreed to join the project on keyboards. The forthcoming Black Widow album has a working title Sleeping With Demons.Tony Martin will be featured on the album as a guest vocalist.
Black Widow's most popular song Come to the Sabbat has been covered by many bands including Timberjack (Top 10 hit in New Zealand in 1971), Bewitched, Death SS and Propagandhi.