Vaclav Havel, 75, the writer and dissident whose eloquent dissections of communist rule helped to destroy it in revolutions that brought down the Berlin Wall and swept Mr. Havel himself into power, died in the Czech Republic on Sunday.
A Czech Embassy spokesman in Paris, Michal Dvorak, said in a statement that Mr. Havel, a heavy smoker for decades who almost died during surgery for lung cancer in 1996, had been suffering from severe respiratory ailments since the spring.
"His peaceful resistance shook the foundations of an empire, exposed the emptiness of a repressive ideology, and proved that moral leadership is more powerful than any weapon," President Obama said Sunday.
A shy yet resilient, unfailingly polite but dogged man who articulated the power of the powerless, Mr. Havel spent five years in and out of communist prisons, lived for two decades under secret-police surveillance, and endured the suppression of his plays and essays. He served 14 years as president, wrote 19 plays, and remained one of his generation's most seductively nonconformist writers.
All the while, he came to personify the soul of the Czech nation. His moral authority and his moving use of the Czech language cast him as the dominant figure during Prague street demonstrations in 1989 and as the chief behind-the-scenes negotiator who brought about the peaceful transfer of power known as the Velvet Revolution.
He was chosen as democratic Czechoslovakia's first president, a role he insisted was more duty than aspiration, and after the country split in January 1993, he became president of the Czech Republic.
Both as a dissident and as a national leader, Mr. Havel impressed the West as one of the most important political thinkers in Central Europe. He rejected the notion, posited by reform-minded communist leaders such as Mikhail S. Gorbachev in the Soviet Union and Alexander Dubcek in Czechoslovakia, that communist rule could be made more humane.
Mr. Havel helped found Charter 77, the longest-enduring human-rights movement in the former Soviet bloc, and articulated the lasting humiliations that communism imposed on the individual.
After the Soviets sent tanks to suppress the Prague Spring reforms in August 1968, Mr. Havel persisted in the fight for political freedom. In August 1969, he organized a petition of 10 points that repudiated the politics of "normalization" with the Soviet Union. He was accused of subversion, and in 1970 was vilified on state television and banned as a writer.
In 1977, Mr. Havel was one of three leading organizers of Charter 77, a group of 242 signers who called for the human rights guaranteed under the 1975 Helsinki accords. Mr. Havel was quickly arrested, tried, and convicted of subversion, and served three months in prison. He was arrested again in May 1979 and was sentenced to 41/2 years.
Mr. Havel's chance at power came in November 1989, eight days after the Berlin Wall fell, when the police broke up an officially sanctioned student demonstration.
Two days later, Mr. Havel convened a meeting in the Magic Lantern, a Prague theater, and he and other dissidents established the Civic Forum. It called for the resignation of the leading communists, investigation of the police action, and the release of all political prisoners. The next day, an estimated 200,000 people took to the streets in Prague, the first of several demonstrations that ended communist domination.
Mr. Havel's role evolved into one of educator and moral persuader. He championed, for instance, the rights of Gypsies, or Roma, despite surveys that showed that most Czechs would not want a Gypsy as a neighbor.
While many in the West lionized Mr. Havel - President Bill Clinton once compared him to Mohandas K. Gandhi, and in 1994 he was awarded the Philadelphia Liberty Medal - in his native country he was regarded with deep affection but also with ambivalence, and even scorn. His slogan during the revolution that truth and love must prevail over lies and hatred was mocked by foes, who accused him of naivete.
Erik Tabery, a Czech journalist and author of a book on the Czech presidency, said some Czechs resented Mr. Havel for holding up an uncomfortable mirror to their history of passivity.
"While the communists ruled for 40 years, most Czechs stayed at home and did nothing," Tabery said. "Havel did something."
After stepping down as president in 2003, Mr. Havel, ailing and tired, returned to writing, insisting he was happy with a peaceful life. In his memoir, To the Castle and Back, published in 2007, he called his political rise an accident of history. Post-communist society disappointed him, he said.
He continued to worry about what he called "the old European disease" - "the tendency to make compromises with evil, to close one's eyes to dictatorship, to practice a politics of appeasement."