Foreign Secretary William Hague has hailed the legacy of "Cold War hero" Vaclav Havel as he led British tributes following the former Czech president's death.
The dissident writer, elected to lead the transition after the communist regime was swept away in the peaceful Velvet Revolution of 1989, died this morning after a long illness.
"Cold War hero, playwright and President. He opened the door to democracy in Eastern Europe and will always be remembered," Mr Hague posted on Twitter.
The death, aged 75, of the man who famously ridiculed the communist state as "Absurdistan" drew emotional responses from across Europe and the globe.
Swedish premier Carl Bildt hailed Mr Havel, who was several times nominated for the Nobel Peace Prize, "the greatest European of our age".
A chain smoker who had long suffered respiratory trouble, the former president's revolutionary motto was: "Truth and love must prevail over lies and hatred."
Then US president George W Bush, when bestowing America's highest civilian award on him, said it was for being "one of liberty's great heroes".
As well as steering the country into democracy, Mr Havel also oversaw the peaceful split of the country in 1993 into the Czech Republic and Slovakia.
Prime Minister David Cameron said: "I am deeply saddened at the death of Vaclav Havel. Havel devoted his life to the cause of human freedom. For years, communism tried to crush him and to extinguish his voice. But Havel, the playwright and the dissident, could not be silenced."
Deputy Prime Minister Nick Clegg said: "Vaclav Havel was a towering figure in the transformation of central and eastern Europe after the collapse of the Berlin Wall - inspiring me and many people of my generation. He straddled the worlds of art and politics providing a uniquely principled, thoughtful style of leadership. Above all, he was that rarest of politicians: a genuine revolutionary who helped transform his country for good."