Einstein spent his childhood in Munich, Germany. his early education was at schools in Munich and at Aarau in Switzerland. In 1896 he entered the Technische Hochschule in Zurich, Switzerland, from which he graduated in 1900. In the following year Einstein married Mileva Marec, and the couple had two sons before their marriage was dissolved in 1916.
In 1902, Einstein went to work in the Swiss patent office, while studying for his Ph.D. degree at Zurich University. It was during this period that he did most of his important work. In 1905, at the age of 26, he published three major papers. These were his photoelectric law, his theory of Brownian movement, and his special theory of relativity.
As these contributions to science became known and recognized, Einstein rose in the academic world. He became a professor, first at the University of Zurich, then at the German university in Prague, and later at the Technische Hochschule in Zurich. In 1913 he accepted a research appointment at the Prussian Academy of Sciences in Berlin, and in 1914 he again became a German citizen. In addition to his research appointment he accepted the positions of professor at the University of Berlin and director of the Kaiser Wilhelm Institute of Physics.
In 1916, Einstein published the general theory of relativity, which was tested and partially verified by astronomers during the solar eclipse of 1919.
In 1932, Einstein visited California and decided to emigrate to the United States because of the rise of Nazism in Germany. He returned to Europe in 1933, resigned from his positions, and came to the United States. He brought with him his second wife, Elsa, who was his cousin and whom he had married in 1917. In 1933 he became a member of the Institute for Advanced Study at Princeton, N.J.
Einstein became a U.S. citizen in 1940 and served the U.S. Navy as a scientific adviser during World War II. He retired from his post at Princeton in 1945 but continued his work there until his death, having published parts of his unified field theory in 1950 and 1953.
Einstein was a shy man who was very much absorbed in his work. However, his absorption in his work did not prevent him from being interested in world events. Although Einstein contributed to the U.S. war effort in World War II and recommended the development of the atomic bomb, he was a fervent pacifist who tried to work toward the eventual end of war. He believed that a system of world government was necessary to ensure world peace.