He describes life at home with a man usually remembered as a prolific murderer and insatiable womaniser: ‘He liked history and loved books. He had a very good library. All of us were educated people.’ A rocket scientist by training, Sergo remembers the family mansion on Vspolny Lane, where they lived after moving from Tbilisi to Moscow in 1938, as a sanctuary of civilised conversation. Vistors, he said, included the Cambridge spy, Kim Philby, the American nuclear scientist, Robert Oppenheimer, and Golda Meir, Israel’s ambassador to Moscow. A frequent caller was Stalin’s daugher, Svetlana, whom he remembers fondly as a lost little girl but whom he also criticises for turning against her father, whom Sergo never refers to as Stalin but always by the more cosily respectful Josef Vissarionovich.