He also revealed a secret: He nearly went on the Hatton Garden job himself. He said that the gang had tried to recruit him and he regretted that he hadn’t gone. At the time, he was 82. “I was too old to fancy going to work, but it would’ve been one last roll of the dice,” he said.

Image Holes bored through a 20-inch-thick concrete wall into a vault in Hatton Garden, London, where millions of pounds of gems, gold and cash were stolen by a group of aging thieves in 2015. Credit... British Metropolitan Police, via Agence France-Presse — Getty Images

Mr. Foreman’s apartment is cramped, but he doesn’t need much room after more than a decade of living in a prison cell, “my every movement watched by screws,” he said, referring to prison guards. He is sprightly in manner, but sometimes uses a walking stick, and two strokes and triple bypass surgery have slowed him down. He still works out, using two purple dumbbells.

A shelf is crammed with memories of his former life: a black-and-white portrait of him as a scrappy 17-year-old bare-knuckle boxer, a photograph of the Kray twins. There are stacks of gangster films, along with a biography, “The Dark Charisma of Adolf Hitler.”

Paul Van Carter, director of “Fred,” a chilling 2018 documentary about Mr. Foreman’s life, called him the last living legend among the “old school London heavy gangsters” who came of age on the mean streets of the British capital after World War II. “I consider him a businessman who operated in the criminal world,” Mr. Van Carter said. “He was charming, intelligent, loyal to his friends and as feared as he was respected.”

Mr. Foreman’s journey from “Brown Bread Fred,” (“brown bread” is Cockney rhyming slang for “dead”), to retired pensioner has been variously marked by hardship, opulence, menace and a canny instinct for survival.

One of five sons of a taxi driver and a housewife, the violence and poverty of his childhood in London during the war helped form him. “I remember being blown out of my bed by an explosion and seeing children’s bodies on the streets,” he said.

“I didn’t have an education,” he added. “If I had, my life could’ve turned out differently.”

Mr. Foreman’s criminal career began in the 1940s at age 16 when he lived in Battersea, in South London, then a tough neighborhood. Handsome and strong, he said he apprenticed with a band of female thieves, who stuffed their bloomers — their underwear — with stolen mink furs, jewelry and clothing.