There is much about Berlin that is, and will continue to be, disputed: the true value of his work, his politics, the degree of his involvement in the cultural Cold War and his Zionism. The value of his correspondence, though, is beyond dispute. In a letter to the American novelist Mary McCarthy, Berlin explained his “devotion” to the eccentric interior designer Rowland Burdon-Muller. He was, Berlin explained, “the last witness of his age” who had known many influential figures of the fin de siècle. “The story of his relations with Proust is marvellous,” wrote Berlin. Berlin was himself one of the great witnesses of his age and the final volume of his letters will complete one of the most important collections of correspondence of the century.