Festivals are primarily religious feasts organized to honour the memory of the saint to whom a local church is dedicated. The faithful often gather in the churchyard or other nearby open space to take part in festivities such as dancing, singing or eating. Trade fairs are outdoor markets set up during a religious festival for the sale of animals and produce. They are usually non-permanent affairs linked to a particular feast.

In Byzantium and Greco-Roman antiquity, festivals contributed to the growth of trade, particularly in provincial towns, and drew large numbers of people together for religious, recreational and other activities. Fairs yielded significant economic benefits for the state; civil servants acting on behalf of the central administration collected the kommerkion, a tax equal to 10% of the value of the products sold, from all participating merchants. At the same time, the gathering of so many faithful paid dividends and income to the local church authorities, especially if the festivals took place at major pilgrimage centres, such as those at the Monastery of St. Simeon the Stylite near Aleppo, St. Demetrios in Thessaloniki (where the feast lasted eight days) and St. Eugene in Trabzon. Key factors in the holding of fairs were the geographic location of a town, and whether or not it had a port or a major road to facilitate the movement of people and goods.  Apart from merchants, many visitors travelled from afar to buy what they deemed necessary.

The duration of fairs was not fixed; they could last several days or only a few, depending on local demand or tradition. Nor was the venue predetermined, as on some occasions they were held in front of the church and on others outside the city walls. Open, level areas were preferred, affording merchants space to spread out their wares, which included utensils, fabrics, carpets, hides and animals (horses, cattle, sheep and pigs), and room for buyers to move with greater ease between the stalls. Areas outside the city walls were also preferred for safety reasons, as the visitors often included foreigners who might prove to be spies or enemies. The Justinian code stipulated that fairs between the Byzantines and the Persian kingdom could only be held in peacetime, at specified sites. Arabs moved often by ship; when they sailed to the seaport of Demetriada (present day Volos) in 904 and explained to alarmed city officials they were merchants, they were allowed to set out their wares outside the city walls. However, as night fell they found the opportunity to scale the walls and open the city gates, killing the guards. As more Arab ships arrived with reinforcements, they subsequently managed to conquer the city.

Nevertheless, fairs were not as a rule dangerous. Whether permanent or improvised, the fairground was central to the social life of inhabitants in the Byzantine Empire. Church writers often criticized the entertainment and relaxation offered at fairs, as well as the conduct of trade and ill-motivated economic activity, since they promoted the spirit of profit and lax morals. Yet the prevailing atmosphere was for the most part pleasant, and offered everyone a chance to forget their problems, socialize and have fun. The entertainment included impromptu performances by wandering troupes of mimes, skilled acrobats, tightrope walkers and magicians, as well as demonstrations of animals playing or dancing to the sound of drums. Magical tricks were also popular with children and adults; some consulted charlatan astrologers and healers who sold herbs or charms. Lastly, they were impressed by physically unusual individuals such as giants, dwarfs or conjoined twins, who were put on display in public places and paraded around the streets.