Friday 11 March marks 20 years since Mikhail Gorbachev rose to power in the former Soviet Union. Artem Krechetnikov of BBC Monitoring looks at the backroom deal that eased his path to the top.
After the death of Konstantin Chernenko on 10 March 1985, the question of a new leader for the Soviet Communist Party was resolved with lightning speed.
The Politburo met less than 24 hours later. Foreign Minister Andrey Gromyko proposed Mikhail Gorbachev as general secretary and all 17 other members supported him.
Mikhail Gorbachev cut a deal with Foreign Minister Andrei Gromyko
The choice was obvious. Most members of the Politburo could not hope to become leader because of their advanced age.
And Chernenko made Mr Gorbachev his unofficial deputy after he took up the post, giving him the job of chairing Politburo meetings in his absence.
But not everything was that simple. Mr Gorbachev had his opponents. It seems that "Operation Successor" was carried through with great speed to prevent them getting organised.
Witnesses report that two powerful men - the chairman of the USSR Supreme Soviet, Nikolai Tikhonov, and the head of the Ukrainian Communist Party, Vladimir Shcherbitsky - were very cool towards Mr Gorbachev.
Mr Gorbachev passed a message back to Mr Gromyko saying he "knew how to keep his promises"
And the first secretary of the Moscow City Communist Party, Viktor Grishin, even drew up his own list of the new Politburo, in which Mr Gorbachev's name did not feature at all.
It was the "human factor", as Mr Gorbachev himself called it, which largely determined how things turned out.
Ever-smiling and accommodating, like a respectful son, Mikhail Gorbachev was more popular with the elderly Politburo members than his main rival, the tough and surly 61-year-old Grigory Romanov.
Romanov was in charge of the military industrial complex and had the support of the military - but his position was severely weakened by the death of the influential defence minister, Dmitri Ustinov, at the end of December 1984.
Three-and-a-half months earlier, another leading marshall, Chief of Staff Nikolay Ogarkov, had been dismissed - unexpectedly for everyone, including himself - while Romanov was heading a delegation in Ethiopia.
But the decisive Politburo meeting was also preceded by behind-the-scenes negotiations, involving Gromyko's son Anatoly, director of the Africa Institute.
He made contact with Mr Gorbachev through another academic, Alexander Yakovlev, later known as the "architect of perestroika" and a close Gorbachev adviser.
Gromyko junior told Mr Yakovlev that his father was tired of working at the foreign ministry and was ready to "play an initiating role at the forthcoming Politburo meeting" if, in exchange, he was given a sinecure position as chairman of the presidium of the Supreme Soviet.
Gromyko stressed the candidate's intellectual qualities - his erudition, analytical capabilities and 'ability to quickly and precisely grasp the essence of the issue'
Mr Gorbachev passed a message back to Mr Gromyko saying he "knew how to keep his promises".
According to Mr Yakovlev, there followed a one-to-one meeting between Gromyko senior and Mr Gorbachev, during which they appear to have reached full agreement.
As a result, the Politburo meeting passed without a hitch. Grishin, followed by Romanov, backed Gromyko, knowing that the result was pre-ordained.
An extraordinary plenum of the party Central Committee was held immediately. In fact, while the Politburo meeting was going on, its urgently convened leaders were waiting in the next room.
Ironically, the future politburo hardliner Yegor Ligachev, who was to become Mr Gorbachev's bitter rival, held preliminary discussions with key regional party secretaries, giving them the nod to support Gorbachev.
Unlike the minutes of the Politburo meetings, speeches made at the plenum were published in Soviet newspapers.
Mr Gorbachev opened the meeting himself. He said a few sentences about the loss suffered by the party, with the death of Chernenko, then immediately gave the floor to Gromyko.
According to party custom, Gromyko spoke not in his own name, but said straight away that the profile of Mr Gorbachev he was presenting was a collective opinion.
He stressed the candidate's intellectual qualities, paying tribute to his extensive erudition, analytical capabilities and "ability to quickly and precisely grasp the essence of the issue".
As was the custom, the new general secretary made a speech in reply. Unusually, it did not contain words of thanks for his appointment. Mr Gorbachev only made the most general and restrained remarks on the tasks facing the country. The term "perestroika" did not appear.
So 11 March 1985 was the start of a new era.
The historian Andrey Dantsev has compared the number 11 to drumsticks, beating out a signal to an era bridled and ready to go off at a gallop.