Mercuralia was the Roman festival held on May 15 to honor Mercury, the Roman counterpart of Hermes.
The festival was associated with merchants and commerce because Mercury was the god of trade, financial gain, travelers, and communication. On the festival day, merchants gathered water from the Porta Capena and sprinkled it over themselves and their goods, asking Mercury to cleanse past dishonesty and support future business.
Mercury’s identity overlaps strongly with Hermes, but Roman religion gave the deity its own traditions and civic setting. The name Mercuralia comes from Mercurius, the Latin name for Mercury.
Mercuralia is distinct from Saturnalia, which honored Saturn, and Floralia, which honored Flora. Lupercalia was a separate February festival with associations involving purification and fertility.