History of the IAU

This text describes the birth and early development of the International Astronomical Union, the world-wide union of professional astronomers that over the past 75 years played an important role in the development of astronomy. Much attention is also paid to the Union's successful bridging political controversies and maintaining the ties between astronomers in times of war or heavy political tension. The book should be of interest not only to astronomers - professional as well as amateur - but also to students of the history of modern science in general. The author who earlier published a study of the history of the European Southern Observatory, is an emeritus professor of astronomy of the Universities of Groningen and Leiden, and has witnessed the development of the Union over the past 55 years, the years 1976-1979 as its President.