Astronomy and the IAU in the next century

The first hundred years of the IAU have witnessed scientific and technological progress in astronomy beyond anything imagined at the time the IAU was founded in 1919. What will the next hundred years bring? How do we engage with other sciences, now that our field is becoming more multidisciplinary? How do we convince governments to continue funding our field, in particular the ever more powerful telescopes? And how do we continue to inspire and involve people worldwide in our exciting adventure through space? A brief forward look into the next decade and beyond is presented, with some challenges highlighted.