Ms. Lennon, then Cynthia Powell, met Lennon when he was a student at the Liverpool College of Art in the late 1950s. She ended her engagement to another man, he broke up with his girlfriend, and they began dating. She became pregnant in 1962 and married Lennon on Aug. 23, just weeks before the Beatles recorded their first single, “Love Me Do.” She was ill prepared for the fame that engulfed John and his bandmates. Their son was born in April 1963, as Beatlemania was spreading across England. Brian Epstein, the Beatles’ manager, hid the existence of Lennon’s wife and son to make him seem available to the legions of young women obsessed with him. John and Cynthia Lennon divorced in 1968, and she received a reported settlement of £100,000 (roughly $240,000 at the time). After the divorce, Lennon cut off contact with her and their son for years, and many accounts of the Beatles’ history minimized them. Cynthia Powell was born in Blackpool, Lancashire, on Sept. 10, 1939. She was married four times, most recently to Noel Charles, who died in 2013. Julian, who is also a singer and songwriter, is her only immediate survivor.