Astronomy in ancient and medieval societies was, in the first instance, practical knowledge. Observation, measurement, modelling, and prediction were employed in and motivated by time-reckoning and calendrics, religion and cult, state and private divination, astrology, and medicine. Applications constrained not only astronomy’s practices and theory but also the social status and training of astronomers. Our symposium explores “astronomy at work” across early societies (Mesopotamia, Greco-Roman, West Asia, Medieval Europe, Islam, South and East Asia).