When Pink Floyd reunited for a performance at Live 8 in 2005, dormant hopes for a more extensive reunion awoke with a vengeance. At various times since, band members have both encouraged and discouraged such hopes. Roger Waters and David Gilmour have expressed more interest in continuing their solo careers than in trying to re-create Floyd's past glory. With the death of keyboardist Rick Wright, reunion hopes are fading again. But if we've learned anything from the band's history, it is to refrain from taking anything for granted. Our timeline recaps memorable milestones in Pink Floyd history.

1965 Capitol/EMI Archive The band forms, consisting of Bob Klose and Roger Waters on guitars, Nick Mason on drums, Rick Wright on keyboards and wind instruments, and Chris Dennis as lead vocalist. Dennis is quickly replaced by Syd Barrett. Klose, who was more interested in jazz and blues, left before the group's first single, "Arnold Layne" was recorded.

1967 First album is released. The Piper At The Gates Of Dawn reaches #6 on the UK album chart but makes it no higher than #131 in the US. The album gets special attention in Britain when the band goes on tour with the already popular Jimi Hendrix.

1968 With Syd Barrett's behavior becoming increasingly erratic, David Gilmour replaces Barrett and the band begins to move from psychedelic to progressive with the release of A Saucerful Of Secrets. .

1969 Two albums were released this year. The soundtrack for the movie, More, Ummagumma was a double album, one disc contained live performances, the other was divided into four sections containing compositions of each member of the band.

1970 Atom Heart Mother is released. The band plays a free concert attended by 20,000 in London's Hyde Park. The band's gear is stolen at a tour stop in New Orleans.

1971 The band embarks on its first tour of Japan, Hong Kong and Australia. Meddle is released. Both Gilmour and Mason would later say that this album served to define Pink Floyd from then on.

1972 The first Pink Floyd single to get significant radio airplay in the U.S., "Free Fun" is first heard. It is from the album Obscured By Clouds, or La Vallee. .

1973 What would become the band's best known, and most commercially successful album is released. The Dark Side Of The Moon has sales of over 40-million. More than three decades later, the groundbreaking concept album continues to sell more copies each week than some of the albums on the Top 200 chart of current releases.

1975 Their performance at the Knebworth Festival set new standards for live shows. It included fireworks and an exploding airplane. Wish You Were Here, a combination of commentary on the music industry and tribute to Syd Barrett, was released.

1977 Of Animals, Rick Wright said in a 1994 BBC interview, "I didn't really like a lot of the music on the album. I think it was the start of the whole ego thing in the band." Nonetheless, the concept album about the perils of capitalism proved to be a commercial success.

1979 The year ofThe Wall and resulted in Waters' banishment of Rick Wright to a minor role in the group for the next few years.

1983 Conflicts between Waters and Gilmour over the band's stylistic direction continue to grow during the recording ofThe Final Cut, which will turn out to be the final Pink Floyd album for Waters. So limited is the participation of other band members that Waters suggests releasing it as a solo album, but the idea doesn't fly.

1985 Roger Waters leaves, proclaiming the end of the band. But when Gilmour, Mason and Wright continue to perform as Pink Floyd, Waters goes to court to try and stop them from using the name. In the end, he loses that fight, and Pink Floyd, minus Waters, forges ahead.

1987 What started as a David Gilmour solo project became Pink Floyd's first post-Waters album, A Momentary Lapse Of Reason. Critics weren't kind, but the album quickly went to #3 on the US and UK album charts. A planned 11-week tour in support of the album ultimately lasted almost two years.

1994 The band's final studio album, The Division BellP*U*L*S*E, is released the following year.

1996 Pink Floyd is inducted into the Rock and Roll Hall of Fame. All except Waters and Barrett attend the induction ceremony. Mason accepts the award, but doesn't join Gilmour and Wright for their performance of "Wish You Were Here."

2005 The last Pink Floyd concert that included both Gilmour and Waters occurred in London in July 2005 at the Live 8 benefit. When reunion fever ensued, band members confided that there were enough of the old tensions apparent during rehearsals to cast doubt on the prospect of anything more than a one-off reunion. That seemed to be borne out in 2007 when Waters performed solo while Gilmour, Mason and Wright performed together at a benefit for their late bandmate, Syd Barrett.

2006 Syd Barrett died at the age of 60 of complications from diabetes in July 2006. It was Barrett who wrote most of Pink Floyd's groundbreaking debut album, The Piper at the Gates of Dawn, released in 1967. He left the band in 1968 as his increasing mental instability was made worse by heavy drug use. He recorded two solo albums before leaving the music business altogether. He died in Cambridge, England, where he was born and had lived quietly since dropping out of public view.