In the 1920s, Einstein used his celebrity to speak out on Zionism, pacifism and democracy as often as he did to debate the finer points of relativity. Touring abroad regularly at the behest of various Zionist groups, Einstein became a prime target for the anti-Semitic forces gathering strength in his native Germany. He is pictured here flanked by leading Zionists Meachim Usishkin, Chaim Weizman, the future president of Israel, and Theodor Benjamin Herzl.

PHOTO: BETTMANN/CORBIS