In early Christian heresiology, the Panarion (Koine Greek: Πανάριον, derived from Latin panarium, meaning "bread basket"), to which 16th-century Latin translations gave the name Adversus Haereses (Latin: "Against Heresies"), is the most important of the works of Epiphanius of Salamis. It was written in Koine Greek beginning in 374 or 375, and issued about three years later, as a treatise on heresies, with its title referring to the text as a "stock of remedies to offset the poisons of heresy." It treats 80 religious sects, either organized groups or philosophies, from the time of Adam to the latter part of the fourth century, detailing their histories, and rebutting their beliefs. The Panarion is an important source of information on the Jewish–Christian gospels, the Gospel of the Ebionites, and the Gospel of the Hebrews.
The treatise can be considered a sequel to the Ancoratus (374), which takes the form of a letter to the church of Syedra in Pamphylia, describing how the "barque" of the church can counteract the contrary winds of heretical thought, and become "anchored" (ἀγχυρωτός); hence the title of the work; the Ancoratus even outlines the content of the Panarion within its text.