Xenia is the ancient Greek concept of hospitality, the generosity and courtesy shown to those who are far from home and/or associates of the person bestowing guest-friendship. The rituals of hospitality created and expressed a reciprocal relationship between guest and host expressed in both material benefits as well as non-material ones.
Jupiter and Mercurius in the House of Philemon and Baucis (1630–33)
by the workshop of Rubens: Zeus and Hermes, testing a village’s practice of hospitality,
were received only by Baucis and Philemon, who were rewarded while their neighbors were punished.
The Greek god Zeus is sometimes called Zeus Xenios in his role as a protector of travelers. He thus embodied the religious obligation to be hospitable to travelers. Theoxeny or theoxenia is a theme in Greek mythology in which humans demonstrate their virtue or piety by extending hospitality to a humble stranger (xenos), who turns out to be a disguised deity (theos) with the capacity to bestow rewards. These stories caution mortals that any guest should be treated as if potentially a disguised divinity and help establish the idea of xenia as a fundamental Greek custom.
The term theoxenia also covered entertaining among the gods themselves, a popular subject in classical art, which was revived at the Renaissance in works depicting a Feast of the Gods.