The couple married in 1962 and divorced in 1968. Julian Lennon is their son.
Expected to fetch at least $25,000, the 1976 typewritten message was the ex-Beatle's response to an open letter to him Cynthia published in News of the World. He sent it to an unnamed U.S. magazine, with a handwritten message on the back asking for it not to be edited when published.
John began by claiming the couple's marriage "was over long before the advent of L.S.D. or Yoko Ono ... and that's reality!"
Among the other noteworthy comments:
- He tells her, "Your memory is impaired to say the least."
- John claimed Cynthia visited him in 1974 and tried convince him to reconcile with her -- and have another child together; but he declined because he was still in love with Yoko Ono.
- He denied hiring a private detective to spy on her and her second husband Roberto Bassanini (to whom she was married from 1970 to 1973).
The letter was signed, "John" with Lennon adding a small sketch of his face.
Cynthia Lennon died in 2015.
Source: RRAuction.com photo credit - NBC Television/Wikimedia