Former Beatles guitarist George Harrison wrote "All Things Must Pass" in January of 1969. Originally planned to be on the Beatles' Let It Be album, the song didn't make the final cut. There's debate over whether John Lennon and Paul McCartney didn't really like the song, or if George wasn't fully up to having his band mates perform with him on this particular track. The song was later released in late 1970 over Harrison's highly-acclaimed album of the same name.
According to Wikipedia, author Elliot Huntley described the song as a "haunting hymn about the mortality of everything." Some have speculated that Harrison was writing about the Beatles slow descent towards their break-up during that period, but others have noticed that Harrison's solo version of the song may have taken on an added dimension, after the death of his mother, Louise, in July 1970 at the age of 59.