This Companion presents both an introduction to the history of the ancient philosophical school of Epicureanism and also a critical account of the major areas of its philosophical interest. Chapters span the school's history from the early Hellenistic Garden to the Roman Empire and its later reception in the Early Modern period, introducing the reader to the Epicureans' contributions in physics, metaphysics, epistemology, psychology, ethics and politics. The international team of contributors includes scholars who have produced innovative and original research in various areas of Epicurean thought and they have produced essays which are accessible and of interest to philosophers, classicists, and anyone concerned with the diversity and preoccupations of Epicurean philosophy and the state of academic research in this field. The volume emphasises the interrelation of the different areas of the Epicureans' philosophical interests while also drawing attention to points of interpretative difficulty and controversy.