Thunder are an English hard rock band from London. Formed in 1989, the group was founded by former Terraplane members Danny Bowes (vocals), Luke Morley (guitar) and Gary "Harry" James (drums), along with second guitarist and keyboardist Ben Matthews and bassist Mark "Snake" Luckhurst. Originally signed to EMI Records in the UK, the band released their debut album Backstreet Symphony in 1990, which reached number 21 on the UK Albums Chart and number 114 on the US Billboard 200. The 1992 follow-up Laughing on Judgement Day reached number 2, while both albums were certified gold by the British Phonographic Industry (BPI). All nine singles released from the two albums reached the UK Singles Chart top 40.

Luckhurst left the band in late 1992, and was replaced the following February by former Great King Rat bassist Mikael Höglund. The new lineup recorded only one studio album, Behind Closed Doors, which peaked at number 5 in the UK and spawned three UK top 40 singles. The 1995 compilation Their Finest Hour (And a Bit) reached number 22 in the UK and was certified silver by the BPI. Höglund left in 1996 and was replaced by Chris Childs, after Morley performed bass on fourth album The Thrill of It All, which reached the UK top 20. Thunder's 1998 live album Live reached number 35 on the UK Albums Chart, while the following year's fifth studio album Giving the Game Away reached number 49. The band broke up in early 2000 due to "outside business forces".

After a brief hiatus, Thunder returned in 2002 and formed their own record label, STC Recordings. The band's sixth studio album Shooting at the Sun was released the following year, supported by the UK top 50 single "Loser". After three more new studio albums – 2005's The Magnificent Seventh, 2006's Robert Johnson's Tombstone and 2008's Bang! – Thunder decided to break up in 2009. Two years later, however, the group returned for a third active spell, scheduling a number of sporadic live shows over the following years. A tenth studio album, Wonder Days, was released on the earMusic label in 2015, giving the band their first UK top ten since 1995 when it peaked at number 9. Rip It Up followed in 2017, reaching a peak UK Albums Chart position of number 3.

On 1 January 1989, at the group's annual New Year's Day meeting, Terraplane was disbanded by vocalist Danny Bowes and guitarist Luke Morley, who decided to form a new band under the name Thunder. Later in the month, the pair recorded a number of demos at Great Linford Manor Studios in Milton Keynes with producer Andy Taylor and engineer Ben Matthews, as well as Terraplane drummer Gary "Harry" James, who was brought in after the initially planned drummer failed to attend. According to Morley, the band name was chosen as a combination of two elements: a song he had written called "Distant Thunder", and Taylor's debut solo album. Enlisting Bad Company's Steve Price to play bass temporarily (Morley played bass as well as guitar on the Linford Manor demos), the group invited a number of record labels to their rehearsals in London, and later signed with EMI in April. Mark "Snake" Luckhurst joined Thunder as the group's original bassist on 2 May 1989, having been recommended by James after the two had performed together in Hellfire Corner. The band's lineup was completed with the addition of Matthews, who had earlier played keyboards for Terraplane's last two shows and engineered Thunder's January demos. Thunder played their first live show on 13 July 1989 at the Reid's Club in Southend-on-Sea, the first date in a short run of seven UK dates dubbed "The Toilet Tour". In August the band returned to the Great Linford Manor to record their debut studio album, again working with Taylor as producer. The album was mixed at London's AIR Studios by Mike Fraser, who also engineered the record. "She's So Fine" was released as the first single from the upcoming album on 30 October, after which the band embarked on a 27-date tour of the UK and Ireland dubbed the "Static Discharge Tour", which included two shows supporting Aerosmith at the NEC Arena in Birmingham. "Dirty Love" was released in February 1990 and entered the UK Singles Chart at number 40, before peaking the following week at number 32. The band's debut album Backstreet Symphony was released on 5 March and entered the UK Albums Chart at its peak position of number 21. By 1991, it had been certified gold by the British Phonographic Industry (BPI). Four more tracks from Backstreet Symphony were later issued as singles – the title track, "Gimme Some Lovin'", a reissue of "She's So Fine", and "Love Walked In" – all of which reached the top 40 of the UK Singles Chart. Writing for Classic Rock magazine in 2002, journalist Dave Ling claimed that the album was "greeted with critical rapture", calling it "one of the all-time great hard rock debuts". AllMusic's Alex Henderson, however, proposed that while the record "wasn't lacking when it came to spirit and enthusiasm", it displayed Thunder as "[not] the most original or groundbreaking band in the world". Backstreet Symphony was featured at number 7 on the Kerrang! "Albums of the Year" feature for 1990, and in 2008 was voted by the magazine's readers to be the 84th best British rock album of all time. Backstreet Symphony was promoted on a UK tour running from late February through until the end of March, after which Thunder travelled to the United States to perform a pair of shows for American media and meet with EMI's sister label Capitol Records, who had originally released the album in the US. According to journalist Mick Wall, who had been travelling with Thunder for a number of months, "Capitol in America were notorious at the time for not supporting acts signed to EMI in the UK", which resulted in the band splitting with the label shortly after their meeting. Thunder continued touring in support of their debut album, including a stint supporting Heart in April and May, and another supporting Love/Hate in July, both in Europe. On 18 August they performed for the first time at Monsters of Rock, which was headlined by Whitesnake. After splitting with Capitol earlier in the year, the band signed a US deal with Geffen Records in September, who reissued Backstreet Symphony with a new cover the following April. In June 1991, the album peaked at number 114 on the Billboard 200. Singles "Dirty Love" and "Love Walked In" reached number 10 and number 31, respectively, on the Billboard Mainstream Rock chart.

After continuing to promote their debut album Backstreet Symphony in various regions around the world throughout 1991, Thunder began recording their second studio album on 3 February 1992 at Outside Studios, which was later mixed at AIR Studios in June. The band worked with producer Andy Taylor again, although the album was co-produced by Luke Morley. In July 1992, the band supported Iron Maiden on a tour of South America which visited Argentina, Uruguay and Brazil, before they performed at Monsters of Rock for the second time the following month, which was also headlined by Iron Maiden. Also in August, "Low Life in High Places" was released as the first single from the band's second album, reaching number 22 on the UK Singles Chart, before Laughing on Judgement Day itself was released and debuted at number 2 on the UK Albums Chart – the band's highest album chart position to date. The album was Thunder's second release to receive a gold certification from the BPI, which it did in January 1993. Later singles "Everybody Wants Her", "A Better Man" and "Like a Satellite" all registered on the UK Singles Chart top 40 ("A Better Man" peaked at number 18, the highest UK Singles Chart position for the band to date).

Thunder embarked on their Laughing All Over the World Tour on 1 October 1992, beginning with a run of 19 headline shows in the UK supported by Australian band The Screaming Jets. The band saw the year out supporting Extreme on a European tour in November, followed by a short run of dates in Japan in December. By the end of the year, Luckhurst had left the band. Morley has revealed that Luckhurst was sacked from the group, due to an incident in which the bassist threw a birthday cake at photographer Ross Halfin, after he requested for photos of only Morley and Bowes together. He was replaced the following February by Swedish bassist Mikael "Micke" Höglund, who was selected from a number of auditionees for the role including former Terraplane member Nick Linden, who claims he "got down to the last two candidates". The band continued touring throughout the rest of 1993, including a number of festival appearances in the summer, and later toured as their alter egos "Danny & the Doo Wops".

For their third studio album (and first with Höglund), Thunder primarily recorded at Southern Tracks in Atlanta and Rumbo Recorders in Los Angeles, with additional sessions taking place at Jacobs Studios in Farnham, Surrey, Armoury Studios in the Canadian city of Vancouver, British Columbia, and the Record Plant in Los Angeles, where the album was also mixed. Mike Fraser, who had previously engineered and mixed Backstreet Symphony, produced the album alongside Morley. "Stand Up" was released as the album's lead single in December 1994, peaking at number 23 on the UK Singles Chart. Behind Closed Doors followed on 23 January 1995, reaching a peak position of number 5 on the UK Albums Chart and receiving a silver certification from the BPI. "River of Pain" was issued as the album's second single in February, reaching number 31 in the UK, followed by "Castles in the Sand" in April which reached number 30. In June 1995, the band won the Kerrang! Award for Best British Live Act.

The Behind Closed Doors Tour commenced in Germany on 5 April 1995 and included shows in Europe, the UK and Japan, wrapping up on 1 September in Tokyo. Later that month, the band released their first compilation album, The Best of Thunder: Their Finest Hour (And a Bit), promoted by the new song "In a Broken Dream" which reached number 26 on the UK Singles Chart and topped the UK Rock & Metal Singles Chart. The album reached number 22 on the UK Albums Chart, number 3 on the UK Rock & Metal Albums Chart (behind AC/DC's Ballbreaker and One Hot Minute by Red Hot Chili Peppers), and was certified silver by the BPI. The compilation was promoted on Their Finest Set (And a Bit) Tour, which included five shows in five UK cities between 27 September and 2 October.