Dame Stella Rimmington, former head of MI6 and chair of the 2011 Man Booker judging panel, announced tonight that Julian Barnes had won the prestigious award for his novel The Sense of an Ending. This was Barnes’ fourth nomination and he was clearly relieved to have won at last. In her speech Rimmington took aim at the critics who had accused this year’s shortlist of being too dumbed down. And rightly so…