Although they wouldn't officially disband until April 1970, the first signs that the Beatles were starting to come apart at the seams took place on Aug. 22, 1968. A little more than six years to the day since he performed his first show with the group, drummer Ringo Starr walked out during the recording sessions for The Beatles.

Not that anybody knew this at the time. Everybody close to the group had to keep the news out of the press. The staff at Abbey Road Studios could sense the situation internally wasn't as rosy as it appeared on the outside. "Things were getting very strained on Beatles sessions by this time," engineer Peter Vince said in Mark Lewisohn's The Beatles Recording Sessions: The Official Abbey Road Studio Session Notes, 1962-1970. "The engineers would be asked to leave. They'd say 'Go off for a meal' or 'Go off for a drink,' and you'd know they were having heavy discussions and didn't want anyone around."

Eventually, all the tension got to Starr. As he recalled in Anthology:

I felt I wasn't playing great, and I also felt that the other three were really happy and I was an outsider. I went to see John [Lennon], who had been living in my apartment in Montagu Square with Yoko [Ono] since he moved out of Kenwood. I said, "I'm leaving the group because I'm not playing well and I feel unloved and out of it, and you three are really close." And John said, "I thought it was you three!" So then I went over to Paul [McCartney]'s and knocked on his door. I said the same thing: "I'm leaving the band. I feel you three guys are really close and I'm out of it." And Paul said, "I thought it was you three!"

Producer George Martin summed it up in the band's Anthology documentary: "If you go to a party and the husband and wife have been having a row, there's a tension – an atmosphere. And you wonder whether you are making things worse by being there. I think that was the kind of situation we found with Ringo ... He might have said to himself, 'Am I the cause?'"

Ringo Starr went to Sardinia, borrowing the yacht that belonged to his good friend, actor Peter Sellers. But he didn't completely abandon music during that time. He wound up writing "Octopus's Garden." Starr's second solo composition for the group, the song would later be released on 1969's Abbey Road.

Meanwhile, the other three Beatles still had work to do. With McCartney filling in behind the drum kit, they recorded "Back in the U.S.S.R." and "Dear Prudence." But they soon realized they needed Starr, and sent him a telegram asking him to return, saying that they thought he was the best rock n' roll drummer in the world and that they loved him.

He came back to the group on Sept. 4, just in time to film the videos (then called "promotional clips") for "Hey Jude" and "Revolution." The next day, Starr arrived at Abbey Road to find his kit decorated in flowers spelling out "Welcome Back, Ringo."

Years later, Paul McCartney realized that maybe they hadn't given Ringo Starr the positive reinforcement he needed. "I think Ringo was always paranoid that he wasn't a great drummer because he never used to solo," he said in Anthology. "You go through life and never stop and ... tell your favorite drummer that he's your favorite. Ringo felt insecure and he left, so we told him, 'Look man, you are the best drummer in the world for us.' I still think that."