U.S. President Barack Obama on Sunday mourned the death of Vaclav Havel, former president of the Czech Republic. \"I was deeply saddened to learn of the passing today of Vaclav Havel, a playwright and prisoner of conscience who became president of Czechoslovakia and of the Czech Republic,\" the president said in a statement. \"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,\" he said.Obama praised Havel\'s \"seminal role\" in the so-called Velvet Revolution in 1989 that won his people their freedom and \"inspired generations to reach for self-determination and dignity in all parts of the world.\"\"He also embodied the aspirations of half a continent that had been cut off by the Iron Curtain, and helped unleash tides of history that led to a united and democratic Europe,\" Obama said. Havel died from longtime illness in his sleep, aged 75. He became president of Czechoslovakia in December 1989 and served as Czech president from 1993 after Czechoslovakia split into the Czech Republic and Slovakia. He led the Czech Republic until 2003.