When did John Lennon's parents get divorced?

Answer 1

They never did divorce legally. Alf left and was out of contact. This caused problems for Julia who lived in a common law relationship from whom she had 2 additional children. She was not able to marry her would-be husband, Bobby Dykins because she couldn't obtain a divorce from an absent husband.

Answer 2

Never. They were separated in 1940, when Alfred Lennon was away at sea at the beginning of World War II, and he did not return until after the war ended, by which time Julia, thinking he had simply deserted her, had moved in with another man.

While Julia lived with John "Bobby" Dykins in a common-law relationship, and their neighbors called her "Mrs. Dykins", they were not actually married, and she and Lennon were never officially divorced. Her death in 1958 legally freed him to remarry, which he did in the late 1960s, having two sons by his second wife Pauline.