Complex sentence: Sir Michael Vincent Levey, LVO (8 June 1927--28 December 2008) was a British art historian and was director of the National Gallery, London for thirteen years, from 1973 to 1986.
Split into simpler sentences: Sir Michael Vincent Levey, LVO (8 June 1927--28 December 2008) was a British art historian and former director of the National Gallery, London. He served as Director of the National Gallery for 13 years, from 1973 to 1986.