Raise your glasses, it’s the birthday of Vita Sackville-West 9 March 1892 – 2 June 1962 writer, gardener and serial womaniser. Vita’s relationship with Violet Keppel (later Trefusis) is detailed in Portrait of A Marriage, by her son Nigel Nicholson. They met at school and at one point eloped to France. In her autobiography Violet…