Einstein was born into a Jewish family at Ulm, Germany. They moved to Munich the following year, where his father Hermann and his uncle Jakob opened a small electrical and engineering works. His mother, Paulina Koch, encouraged him to study music during his youth, and he became an accomplished violinist, but it was Jakob who inspired his fascination for mathematics. Initially an unremarkable student, he was educated at Munich and Aarau, eventually going on to graduate in physics and mathematics from the Federal Polytechnic University in Zürich in 1900. He became a Swiss citizen in 1905, and was appointed examiner at the Swiss Patent Office (1902-09).
He married fellow student Mileva Maríc in 1903, and they had two sons: Hans Albert and Edward (who later had a mental breakdown). However, the outbreak of World War 1 caused him to be separated from his family - he was in Berlin while they were in Switzerland. They were divorced in 1919. A gifted physicist in her own right, Mileva and Albert would work together on the mathematics of his theoretical thinking. In recognition of this he later gave her the money that came with his Nobel Prize. She gave up physics to look after their son Edward. A second marriage, to Elsa, his first cousin (d.1936), took place in 1919.
From 1905 Einstein published papers on theoretical physics in the prestigious monthly Annalen der Physik, including his special theory of relativity, which in its embryonic form was an essay he had written aged 16. Entitled "Zur Elektrodynamik bewegter Körper" (On the Electrodynamics of Moving Bodies), the theory showed that in the case of rapid relative motion involving velocities approaching the speed of light, puzzling phenomena such as decreased size and mass are to be expected. This provided a new system of mechanics which accommodated James Clerk Maxwell's electromagnetic-field theory, as well as the hitherto inexplicable results of the Michelson-Morley experiments (1881, 1887) on the speed of light. He became professor at Prague in 1911, and at Zürich in 1912, then worked in Berlin, where he was director of the Kaiser Wilhelm Physical Institute (1914-33). On accepting the post in Berlin, he reassumed his German citizenship, relinquishing it again in 1933.
"Die Grundlagen der allgemeinen Relativitästheorie" (The foundation of the General Theory of Relativity) was published in 1916. This theory accounted for the slow rotation of the elliptical path of the planet Mercury, which Newtonian gravitational theory failed to do. Fame and recognition came suddenly in 1919, when the Royal Society of London photographed the solar eclipse and publicly verified Einstein's general theory of relativity. In 1921 he was awarded the Nobel Prize for Physics for his photoelectric law and work in the field of theoretical physics, but such was the controversy still aroused by this theories on relativity that these were not specified in the text of the award.
Einstein was regarded suspiciously in Berlin for his outspoken pacifism and socialism, and also for his Jewish background. He was a supporter of Zionism, pulishing About Zionism (Uber Zionismus) in 1931. After Hitler's rise to power, he was deprived of his post at Berlin and his home at Caputh. He left Germany, and form 1934 lectured at Princeton, NJ, took US citizenship, and became professor at Princeton in 1940.
From the 1930s he was increasingly outspoken in support of world peace. In 1933 he joined with Sigmund Freud to write Warum Kreig? (Why War?). However, when it was brought to his attention by German chemists that the splitting of uranium atoms could result in a mammoth explosion, he carried out experiments at Princeton verifying this possibility, and was persuaded in September 1939 to write to President Roosevelt warning him of the possibility that Germany would try to make an atomic bomb. Despite his pacifism, Einstein felt that force should be used to prevent this happening, and in this way he helped to initiate the Manhattan Project (research work led by Robert Oppenheimer into the creation of the atomic bombs dropped on Hiroshima and Nagasaki), although he was not directly involved in it himself.
After the war, Einstein urged international control of atomic weapons, and protested against the proceedings of the Un-American Activities Senate Subcommittee, which had arraigned many scientists. In 1952 he was offered the presidency of Israel, but declined. He spent the rest of his life trying, by means of his unified field theory (1950), to establish a merger between quantum theory and his general theory of relativity, thus bringing subatomic phenomena and large-scale physical phenomena under one set of determinate laws. His attempt was not successful. After many years of deteriorating health, he died in his sleep in hospital at Princeton.
Einstein ranks with Galileo and Newton as one of the great conceptual revisers of our understanding of the universe. He was the originator of completely new ways of looking at space, time, and gravitational forces, as well being a champion of pacifism and liberalism, and the "grand old man" of world peace.