Riccardo Giacconi was born in Genoa, Italy, in 1931. He began his scientific career in Milan, where he wrote his Ph.D. thesis on the subject of cosmic radiation. In 1959 he left for the United States to work at the private research institute American Science and Engineering Corporation (ASE). Giacconi joined the faculty of Harvard University in 1973 and became the first director of the Space Telescope Science Institute in 1981, which supervised the scientific program of the Hubble Space Telescope. He was General Director of the European Southern Observatory in Garching near Munich from 1993 to 1999. Giacconi returned to the United States in 1999 and since then has been President of the Associated Universities Inc. (AUI) in Washington. He is also employed as a research professor at the John Hopkins University in Baltimore, Maryland. He is now a U.S. citizen.