xxviii GENERAL INTRODUCTION for the fate of his papers dates from 1921, when he agreed to give his corre- spondence to the Prussian State Library for its collection of scientists' papers. During the twenties, some effort was made to save manuscripts, typescripts, and correspondence. In 1928 Miss Dukas came to work for him and began to preserve his papers more systematically. But even then, not everything he wrote was kept. Einstein continued to write many letters by hand, and copies of typed letters were not always retained. He gave manuscripts to friends and donated some to charities certain items were stolen. The flourishing trade in Einstein autographs further dispersed his papers, but it also resulted in the preservation of many items. Shortly after the Nazis came to power, Einstein's papers were sent out of Berlin by Rudolf Kayser, his son-in-law, with the help of the French Embassy. Virtually everything was saved and brought to Einstein's home in Princeton, New Jersey, where it remained until well after his death. Einstein's will, signed in 1950, provided for the eventual donation of his papers to The Hebrew University of Jerusalem. After his death, Miss Dukas and Professor Gerald Holton of Harvard University developed a plan for organizing, cataloging, and annotating the collection and for enlarging it by acquiring copies of missing items. The reorganized material was gradually transferred from Einstein's home to the Institute for Advanced Study in Princeton to constitute the Einstein Archive. Some private papers not trans- ferred to the Archive were recently bequeathed to The Hebrew University of Jerusalem under a separate agreement. This material is still not available. Under Miss Dukas's supervision and with the help of a number of scholars over the next two decades, the Einstein Archive grew to its present dimensions. In 1982 the Archive was transferred to the Manuscript Division of the Jewish National and University Library at The Hebrew University in Jerusalem. The Archive forms the primary documentary basis for this edition. After the establishment of the Einstein Office in 1977 to prepare the papers for publication, a full-sized duplicate of each document was made for editorial use. An extensive and systematic search for additional documents began and will continue. We now have about one thousand non-correspondence items, about nine thousand letters from Einstein, and about thirteen thousand letters to Einstein, in addition to several thousand third-party letters (neither to nor from Einstein) and other documents. Current holdings and the rate at which we are adding documents to our collection suggest an edition of thirty or more volumes.