The former Czech President Vaclav Havel is gravely ill in hospital with respiratory problems. The 72-year-old is reported to be in a serious but stable condition in a Prague hospital. Since the 1990s Havel has undergone treatment for lung cancer and a ruptured intestine.He first became known as a playwright and activist against communism, and was jailed for four years in 1979 on a charge of subversion against the state. He was first elected as president of the then Czechoslovakia in 1989 after the collapse of the communist regime. Four years later, after the country’s breakup, he became leader of the Czech Republic. After two terms in the post he stepped down in 2003, amid deteriorating health.