The concept of guest hospitality was extremely important in ancient Greece. Evidence that Xenia was integral to Greek society can be found in the fact that Zeus, the king of the Gods, was also portrayed as the God of Xenia. Xenia created an obligation for the host to be hospitable to their guests, and conversely, the guests had their own responsibilities too. If either the host or the guest was to break a Xenia rule, there would be severe penalties dealt by Zeus and also by society. Some basic Xenia rules were that the guest could not insult the host, make demands, or refuse xenia. Additionally, the host could not insult the guest, fail to protect the guest, or fail to be as hospitable as possible. It was also customary for gifts to be given to the guest, or for a gift exchange to be conducted between guest-friends. The host-guest relationship was very complicated and placed equal burden on both. This custom of xenia also held a burden of trust, where both the guest and host would have to rely on custom in regards to personal safety. This trust was reinforced by both fear of word getting out that the host had provided improper xenia, and fear of retribution by the gods, since one never knew when a traveller might actually be a god in disguise (for example, in book 1 when Athene disguises herself as Mentes and receives hospitality from Telemachus), come to test the level of your xenia. All travellers were seen as sent by Zeus and under his protection, so giving proper xenia was also a way of showing respect for the gods, especially Zeus in the form of Xenios.
Xenia offers a moral ground in the Odyssey. Greek religion did not have strict moral regulations like modern Catholicism etc, and the Gods possessed a level of humanity and humility (for example, they had flaws, such as Achilles heel). Xenia imposed moral regulations in ancient