On the backbenches he occasionally spoke in the House of Commons on issues of the day. Between 1997 and 2002, he was the Chairman of the International Democrat Union. Hague's profile and personal popularity rose thereafter among both Conservative Party members and the wider public following his spell as Party Leader. He has written a biography of 18th-century Prime Minister Pitt the Younger (published in 2004), taught himself how to play the piano, and hosted the 25th anniversary programme for Radio 4 on the political television satire "Yes Minister" in 2005. In June 2007 he published his second book, a biography of the anti-slave trade campaigner William Wilberforce, shortlisted for the 2008 Orwell Prize for political writing.