He was born in Doncaster, West Riding of Yorkshire, in 1954 to John and Elizabeth Jill Marsh.
After working in Blackburn, Birmingham, and Belfast, he joined the BBC Radio 4 Programme, The World at One - then presented by Sir Robin Day.
In 1996, he became joint editor of both The World at One and PM and in 1998, launched the new Sunday morning news programme Broadcasting House, presented by Eddie Mair.
He became editor of the Today programme in November 2002, succeeding Rod Liddle who had resigned the previous September.
In May 2003, Today became embroiled in a row with the Government over an early morning claim made by reporter Andrew Gilligan that the Government "probably knew" that one of the key claims made in its September 2002 dossier detailing Iraq's WMD "was wrong".