William Mostyn-Owen was an art historian, educated at Eton and Magdalene College. He traveled widely in postwar Italy and France, visiting many private collections as well as the famous museums and galleries and during the 1950s he developed a deep love of the Italian Renaissance through six years of close contact with Bernard Berenson at Villa I Tatti.
"Willy" was enrolled in the Berensonian circle of scholars and acquaintances, among them Harold Acton, Kenneth Clark, Rosamond Lehmann and Hugh Trevor-Roper. After two years spent compiling a bibliography of Berenson's immense array of critical writings, he edited a new English edition of his employer's path-breaking study of Lorenzo Lotto, and (with Luisa Vertova) revised Berenson's publications on Venetian and Florentine painters. After short spells at the Fogg Museum in Harvard and the Metropolitan Museum in New York, he was hired by Christie's, where he was made a director in 1968 and chairman of Christie's Education from 1979 to 1988.
His enduring love of travel served him well when he founded Christie's Tours. He contributed to the Oxford Companion to Western Art and the Macmillan Dictionary of Art and wrote articles for the Burlington Magazine, the Times Literary Supplement and various newspapers.
The bulk of the collection consists of Willy Mostyn-Owen's correspondence with Bernard Berenson, Nicky Mariano and the people he met at I Tatti during his stay in the Villa and in the nearby Villino during the 1950s, as an assistant to the aged art historian, then in his late eighties. The correspondence dates from 1950 on. The other part of the collection regards I Tatti and Berenson, and includes drafts for the bibliography of Bernard Berenson that WMO edited and published in 1955, a file regarding Contini Bonacossi, and a letter sent by WMO to his mother.