In the 1930s, organized crime came to England. The Italian Sabinis and English White family in West End dominated the London underworld. Come WWII and Jack "Spot" took over and later Billy Hill.
Jamie Foreman who plays Alf White, head of the White family street gang, is the son of real-life convicted London gangster Freddie Foreman. Freddie Foreman was convicted of handling the proceeds of an armed robbery. He was also convicted of disposing of the body of Jack "the Hat" McVitie who was murdered by Reggie Kray.
In a scene set in 1939 there are posters for a concert featuring The Platters and Lonnie Donegan and another advertising "A Visit With Floyd Patterson". Both of these seem to be from the 1960s.