Karen Armstrong became a household name in the United Kingdom in the 1980s, thanks to her best-selling books Through the Narrow Gate and Beginning the World, her autobiographical accounts of her life in a Roman Catholic convent during the 1960s. She followed with a successful TV documentary series on St. Paul, and during the '90s she earned a reputation as one of the world's most successful writers on religion, with books such as Muhammad: A Biography of the Prophet (1992), A History of God (1993), and Jerusalem: One City, Three Faiths (1996). Also a part-time university teacher, Armstrong has also published a brief biography of Buddha (2001), a second biography of Muhammad called Muhammad: A Prophet for Our Time (2006) and another memoir, The Spiral Staircase: My Climb Out of Darkness (2004).