She spent some time at Sarah Lawrence College, and then became involved in New York City's downtown artists scene, including the Fluxus group.
The publication of Philip Norman's John Lennon: The Life has reignited speculation over the rock icon's early years.
Written with the assistance of Yoko Ono and Paul Mc Cartney – both of whom are said to be unhappy at the result – Norman describes how Lennon developed into a lonely and vulnerable teenager after he moved in with his aunt Mimi following the collapse of his mother Julia's marriage to the wayward Alfred "Freddie" Lennon.
While she had suspicions of Lennon's infidelity over the years, with friends telling her that Lennon had had numerous affairs as far back as their time together at art college in Liverpool, Cynthia ignored the warnings.
In an interview to publicise one of her books, 2005's John, she told Good Morning America: 'I have read so many books and seen so many films, and it's like we don't really exist.
She first met Lennon in 1966 at her own art exhibition in London, and they became a couple in 1968.
With their performance Bed-Ins for Peace in Amsterdam and Montreal in 1969, Ono and Lennon famously used their honeymoon at the Hilton Amsterdam as a stage for public protests against the Vietnam War.
Produced with Ono, the album was a disappointment after the success of 1971’s ‘Imagine.’ “I was very aware that we were ruining each other’s careers and I was hated and John was hated because of me,” Ono told the Telegraph. You want to get out of that.” Ono knew that Lennon was attracted to their personal assistant, May Pang, and believed that Pang would treat John well.
In an attempt to save their marriage, Ono proposed that Pang begin an affair with Lennon. He was ready to go out with somebody whether it was me or anybody else.” In October, Lennon and Pang went to Los Angeles to promote ‘Mind Games’ and decided to stay.
Lennon referred to the time apart from Ono as ‘The Lost Weekend,’ named after a 1945 film that starred Ray Milland as an alcoholic writer.
Ahead, some of the highlights – and low points – of John Lennon’s “Lost Weekend.” Summer 1973: Lennon and Ono Split Up Lennon’s 1972 LP ‘Some Time in New York City,’ was a critical and commercial flop. Can you imagine every day of getting this vibration from people of hate?