De László was conscious of his reputation both in the present and for posterity and his extensive archive is an unique source of important material for those with an interest in the history of the late 19th and early 20th century. The de Laszlo Archive Trust has donated more than 15,000 items of correspondence and press cuttings to the Heinz Archive and Library at the National Portrait Gallery in London. This collection includes important letters between the artist and some of the most interesting and significant people of the period: presidents, monarchs and courtiers, statesmen and diplomats, soldiers, scientists and churchmen, as well as artists, writers and musicians.

A significant amount of material remains in the Catalogue Raisonné office and continues to be indexed and added to our archive database. Newly discovered and donated correspondence is also being added. One hundred and twenty boxes of material was scanned before the advent of high resolution imaging and there is a wide variation in the quality of digital reproductions available on our website.