JC: In 1927, when Mao was 33, he came into contact with Stalinism, and that was also the year he began to engage in violence. And I think before Stalinism sank into him, Mao’s attitude to violence had been more a traditional Chinese one. There were lots of atrocities and acts of violence committed, but people didn’t think these things were right. Stalinism gave violence an ideological justification: suddenly Mao and the other Chinese communists got instructions from Moscow: “Terror is what we want”. You know, “kill, kill, kill, burn, burn, burn” — those were the actual slogans. You can’t be communist without being brutal. So I think that was a revelation for Mao — you can be brutal, you can be violent, and you can feel fully justified.

SSM: Stalin started much younger. When I started Young Stalin I thought there would be no killing in the book. But then I found out that at a very young age — 22 or so — he was already having supposed traitors wiped out. Obviously he later moved on to millions as Mao did, but at the time it was just one person here and there. With Stalin it was a combination of personality, Georgian traditions, and also studying violence in history: studying the Terror, the Paris Commune, Robespierre.

One thing they had in common was that they both studied history voraciously from an early age. That was very important. Stalin worshipped Robespierre — he used “Robespierre” as a compliment — but he also worshipped Ivan the Terrible and Persian shahs like Nader Shah who was famously brutal.

JC: Yes, in Mao’s vast library most books are about Chinese emperors, and a lot about awful Chinese emperors. Mao’s favourite pastime was to read history. He had these huge beds, half of which would be piled a foot high with books so he could wake up, roll over, pick up a book and start reading.

SSM: Stalin, at the height of the Great Terror, compared himself to Ivan the Terrible, saying that the great thing about him was that he wiped out most of the Boyars, musing that he should have wiped out all of them. He named Ivan as his “teacher”. Walking in the Kremlin, he’d say, “Ivan walked right here”. Mao and Stalin compared themselves continually to these people, even as active communists in a system where they would have killed anybody who used any similar comparison.

JC: In the last couple of years of Mao’s life when he was identifying himself with all these imperial rulers, he never once identified himself with other communist leaders, with the exception of Stalin.