This volume, presenting 465 items of correspondence, is divided into two parts.
The first half of the volume presents 211 supplementary letters to the correspon-
dence already published in Volumes 5, 8, and 9 for the period May 1909 through
April 1920. Of these, 124 letters, most of them written by Albert Einstein, originate
from the bequest of family correspondence deposited at the Albert Einstein
Archives at the Hebrew University in Jerusalem by Margot Einstein (1899–1986),
who stipulated that the material remain closed for twenty years after her death.
Sixty-six letters for this period were obtained from the Heinrich Zangger manu-
script collection of the Central Library in Zurich, where it was deposited by the es-
tate of Gina Zangger (1911–2005). Twenty-one additional letters from other repos-
itories are also included.
The second half of the volume presents 254 letters as full text from among a total
of 614 extant correspondence items for the period May through December 1920.
The editors have sought to present those letters that are representative and signifi-
cant for understanding Einstein’s work and life. Correspondence that is not present-
ed as full text is abstracted and listed chronologically in the Calendar at the end of
The letters for the years 1909 through 1920 presented in the first half of this vol-
ume provide the reader with substantial new source material for the study of Ein-
stein’s personal life and the relationships with his closest family members and
friends. With the exception of Einstein’s early correspondence with Mileva Maric;
prior to their marriage in 1903, which was published in Volume 1 and contained a
number of letters written by both of them, the subsequent family correspondence
available until now has mainly comprised letters written by Einstein himself to Mi-
leva Einstein-Maric; and their two sons, Hans Albert and Eduard, in Zurich, and a
small number of missives to Elsa Einstein, his cousin in Berlin, who became his
second wife in 1919.
The current volume presents for the first time in this series letters written by
Hans Albert and Eduard Einstein. It also includes for the first time since Volume 1
a number of letters written by Mileva Einstein-Maric;. The largest group of letters
INTRODUCTION TO VOLUME 10