Answer by taking a quote from the following article:

Deep Purple are an English rock band formed in Hertford in 1968. The band is considered to be among the pioneers of heavy metal and modern hard rock, although their musical approach changed over the years. Originally formed as a progressive rock band, the band shifted to a heavier sound in 1970. Deep Purple, together with Led Zeppelin and Black Sabbath, have been referred to as the "unholy trinity of British hard rock and heavy metal in the early to mid-seventies".

The end came on tour in England on 15 March 1976 at the Liverpool Empire Theatre. In the words of Jon Lord:  "At one point during the show, Glenn said to the audience, 'I'm sorry we're not playing very well, but we're very tired and jet-lagged.' And I remember spluttering to myself, 'Speak for yourself.' I was working like a Trojan to try and make this work ... Paicey was playing like a madman just to keep it all together ... Coverdale was singing his socks off. So to hear this guy who was extremely high on various substances telling the audience, 'I'm sorry, We aren't playing well' kind of rankled me a bit. I came off stage and went straight to my dressing room, which I was sharing with Ian Paice, and I said, 'Ian ... that's it, isn't it? That's absolutely the end of this band as far as I'm concerned. Why are we doing this to ourselves?' So he and I shook hands and said, 'It's over. Thank God.' About ten minutes later, Coverdale came in, big blustery guy that he is, and he said, 'I'm leaving the band!' And we said, 'David, there's no band to leave.'"  The break-up was finally made public in July 1976, with then-manager Rob Cooksey issuing the simple statement: "the band will not record or perform together as Deep Purple again". Later in the year, Bolin had just finished recording his second solo album, Private Eyes, when, on 4 December 1976, tragedy struck. In a Miami hotel room, during a tour supporting Jeff Beck, Bolin was found unconscious by his girlfriend and bandmates. Unable to wake him, she hurriedly called paramedics, but it was too late. The official cause of death was multiple-drug intoxication. Bolin was 25 years old.  After the break-up, most of the past and present members of Deep Purple went on to have considerable success in a number of other bands, including Gillan, Whitesnake and Rainbow. There were, however, a number of promoter-led attempts to get the band to reform, especially with the revival of the hard rock market in the late 1970s and early 1980s. In 1980, a touring version of the band surfaced with Rod Evans as the only member who had ever been in Deep Purple, eventually ending in successful legal action from the legitimate Deep Purple camp over unauthorised use of the name. Evans was ordered to pay damages of US$672,000 for using the band name without permission.

When did that happen?
In 1980,