Mikhail Gorbachev was courted by Margaret Thatcher in the 1980s as she plotted the ending of the Cold War and later trusted by John Major as a reliable ally.
Even before he became president of the old Soviet Union, Mrs Thatcher described him as "a man one could do business with". And she did, along with her ideological soulmate, Ronald Reagan.
Her courtship began when Mr Gorbachev made a visit to the UK in 1984, at a time when he was expected to be the USSR's next head of state.
Mrs Thatcher desperately wanted to improve personal relations with him and the Soviet Union.
Many will see it as tragic that the warm relations with Mr Gorbachev she achieved during the 1980s, leading to the ending of the Cold War, the collapse of the Berlin Wall and the creation of modern democracies in Eastern Europe, have now been left in tatters by President Putin's brutal war in Ukraine.
Mrs Thatcher literally rolled out the red carpet for Mr Gorbachev during that visit to the UK in 1984, hosting him at Chequers. He was then Number 2 in the Soviet Communist Party hierarchy.
Later, at the funeral of President Chernenko, Mr Gorbachev's predecessor, in 1985, she told the new president his visit had been one of the most successful ever by a major world leader.
Throughout her premiership, no British prime minister had more meetings with a Soviet leader than Mrs Thatcher did with Mr Gorbachev. Not even her hero Winston Churchill with his wartime ally Josef Stalin.
The result was the glittering diplomatic prize of the thawing of the Cold War, for which Mrs Thatcher and Mr Gorbachev must take enormous credit.
When Mr Major succeeded Mrs Thatcher as prime minister, he too wooed Mr Gorbachev at every opportunity.
During a visit the Russian leader made to the UK in 1991, Mr Major took him on an impromptu tour of parliament.
The tour included a visit to the House of Commons terrace, packed with MPs of all parties at the time. With political journalists - including me - in tow, Mr Major introduced his VIP guest to just about every MP on the terrace.
Mr Gorbachev seemed to be enjoying every minute. It was all part of the charm offensive mounted by Mrs Thatcher and Mr Major over many years. And it paid off handsomely.
Mrs Thatcher was right when she said he was a man she could do business with. As Liz Truss prepares to step up from foreign secretary to prime minister, she will wish someone like Mr Gorbachev was in the Kremlin now.