Astronomical and astrological knowledge circulated in many ways in the ancient world: in the form of written texts and through oral communication; by the conscious assimilation of sought-after knowledge and the unconscious absorption of ideas to which scholars were exposed. The Circulation of Astronomical Knowledge in the Ancient World explores the ways in which astronomical knowledge circulated between different communities of scholars over time and space, and what was done with that knowledge when it was received. Examples are discussed from Mesopotamia, Egypt, the Greco-Roman world, India, and China.