Born in Croydon, England, King studied composition under the Webern disciple, Humphrey Searle, and Alexander Goehr at the Royal College of Music and continued studying under Goehr at the University of Southampton, before receiving an Italian government scholarship to study composition under Ernesto Rubin de Cervin and Giuseppe Sinopoli at the Conservatorio "Benedetto Marcello" in Venice from 1973 to 1974. It was in Venice during the 1970s, where he befriended fellow composition students, Marino Baratello and Claudio Ambrosini - all members of the burgeoning, new Venice movement or "school" for contemporary music. From 1976 until 1987 he was on the staff of St Mary's Music School and in 1979, working in partnership with Diana Milne, Peter Nelson and Michael Tilmouth, ECAT (Edinburgh Contemporary Arts Trust) was established. In 1988 King was appointed composer-in-residence at Huddersfield Polytechnic, and also with the NCOS Symphony Orchestra in London. At the same time he moved to The Netherlands, receiving a Dutch government scholarship to study at the Koninklijk Conservatorium in The Hague. In 1995 he moved to Amsterdam where he now lives.