In the band’s early days, John Lennon was understood to be the leader of the Beatles. However, by the middle of the 1960s, Paul McCartney would take the reins. While the band would find continued success under McCartney’s leadership, the shift of power led to the band members growing more distant from each other.

According to Far Out, the origins of this came in 1964, when McCartney broke away from the pair’s collaborative songwriting relationship and wrote “Can’t Buy Me Love,” which took the A-side on their band’s next release. Lennon reacted by writing, “A Hard Day’s Night” and most of the songs on the album of the same name. This song-versus-song dynamic would continue over the rest of the decade. McCartney would write “Yesterday,” and Lennon would follow with “Norwegian Wood.” Lennon would write “Strawberry Fields Forever,” and McCartney would follow with “Penny Lane.” McCartney has said this competition “was a great way for us to keep each other on our toes,” but according to Far Out, “on occasion Lennon’s nose was put out of joint.”

In his book, “Revolution in the Head: The Beatles’ Records and the Sixties,” Ian Diamond writes, “Lennon must have sensed that his era of dominance over the band’s output … was over. From now on, his partner would be in the ascendant not only as a songwriter, but also as instrumentalist, arranger, producer, and de facto musical director of The Beatles.”

By the end of the 1960s, the Beatles were operating under a cloud of tension and resentment. Their manager, Brian Epstein, had died suddenly in 1967, and without him, the group lacked guidance and a figure to act as arbiter in their creative disagreements.

The ending came on September 20, 1969. According to Far Out, despite the pleadings of the group’s new business manager, Allen Klein, not to say anything, John Lennon told Paul McCartney and drummer Ringo Starr he was leaving the group. The breakup did not come as a surprise. As People details, the four members had been living largely separate lives, getting married, having babies, and making music outside of the group (especially Lennon and Harrison). McCartney later said, “I must admit we’d known it was coming at some point because of his intense involvement with Yoko. John needed to give space to his and Yoko’s thing.”

The band kept things quiet for a few months, until, on April 10, 1970, McCartney announced to the public that the band was splitting up, as reported by History.

John Lennon’s and Paul McCartney’s songwriting partnership is remembered today as the greatest in pop music history. But after bonding over a mutual love of music and reaching unimaginable peaks, their relationship soured. During the final years of the Beatles and after the band split, the former friends would spend the next decade in a love/hate relationship. 

According to Biography, the pair met on July 6, 1957, when Lennon was performing with his skiffle band, The Quarrymen. A mutual friend introduced the two, and a few months later, Lennon asked McCartney to join the group. It evolved into the Beatles, with Lennon and McCartney as the main singer/songwriters.

By the time the band broke up, the two were at each other’s throats. They wrote each other angry letters, and Ultimate Classic Rock reports that both men wrote insult songs directed at each other. McCartney’s included “Too Many People,” and Lennon’s response was “How Do You Sleep?,” which features the lyrics “The only thing you done was ‘Yesterday’ / And since you’ve gone, you’re just ‘Another Day.'”

The two eventually reconciled and maintained contact over the final years of Lennon’s life, with McCartney saying, “We just talked kids and baking bread.” McCartney has also said that their last conversation before Lennon’s murder was friendly. Linda McCartney said that Lennon’s final words to McCartney were, “think about me every now and then, old friend.”

While the Beatles were in their final days, a family of pre-teen musicians hit the charts almost as hard as the Fab Four. The Jackson 5 became hugely successful in the late 1960s, and Michael Jackson went on to become a superstar. In the 1980s, Jackson tapped Paul McCartney for a series of duets.

According to Ultimate Classic Rock, McCartney had written a song, “Girlfriend,” for Jackson. The song appeared on the 1978 Wings album, “London Town,” before Jackson included it on his album “Off the Wall.” McCartney and Jackson also came together for “The Girl is Mine” on Jackson’s “Thriller” album and both “The Man” and “Say, Say, Say” for McCartney’s “Pipes of Peace” album.

While working together, McCartney had talked to Jackson about the importance of music publishing and owning catalogs. McCartney had purchased the back catalog of the late rock icon Buddy Holly. Jackson took the advice to heart and in 1985, bought the most sought-after catalog in pop music, that of the Beatles.

After this, the pair never spoke to each other again. McCartney said, “I think it’s dodgy to do something like that. To be someone’s friend, and then buy the rug they’re standing on.” Biography reports that McCartney’s anger towards Jackson only increased when the King of Pop started allowing Beatles songs to be used in commercials.

After the passing of Linda McCartney, Paul McCartney married model and media personality Heather Mills. According to Biography, this drew criticism from Paul’s daughter Stella McCartney, who had mixed feelings about Mills’ and her father’s decision. The union led to a daughter named Beatrice. Unfortunately, after only six years of marriage, Paul and Mills divorced, and the drama was played out in the British tabloids.

Ultimate Classic Rock reports that the pair acquired the lawyers used during the divorce proceedings for Prince Charles and Princess Diana. Attempts to reach a settlement that included a confidentiality failed, and all the details were made public. Mills accused Paul of abuse and rampant drug use, while Paul claimed she was irresponsible and rude to his staff. 

Mills also accused her ex-husband of abusing his first wife, Linda McCartney. Stella McCartney, Paul’s and Linda’s daughter, spoke out against the accusation and even questioned her father for marrying Mills. Both former partners denied each other’s claims, and the divorce was finalized in 2008, with Mills receiving just $30 million after requesting $150 million. She reportedly said that she was “very, very, very, pleased” with the outcome. The judge in the case said that Mills was “a less than impressive witness” and that her evidence “was not just inconsistent and inaccurate but also less than candid.”

Mills said that the press was unreasonably critical and overlooked her 20-plus years of charity. In 2011, Paul married Nancy Shevell, and the pair have been together ever since.