 Agnew was educated at Gresham's School, Holt, from 1964 to 1969 and then at the Royal Agricultural College, Cirencester.He succeeded to the UK baronetcy (Agnew, of The Planche, Suffolk, created 1895) in 1994.The Rougham estates include Rougham Airfield, where Agnew organized a wide variety of annual fairs, rallies and events, including the "Wings, Wheels & Steam Country Fair", the annual "Rougham Air Display & Harvest Fair", and the "East Anglian Medieval Battle & Fair".