The Boedromia (Βοηδρόμια) was an ancient Greek festival held at Athens on the 7th of Boedromion (summer) in the honor of Apollo Boedromios (the helper in distress). The festival had a military connotation, and thanks the god for his assistance to the Athenians during wars. It could also commemorate a specific intervention at the origin of the festival. The event in question, according to the ancient writers, could be the help brought to Theseus in his war against the Amazons, or the assistance provided to the king Erechtheus during his struggle against Eumolpus. During the event, sacrifices were also made to Artemis Agrotera.
Dictionary of Greek and Roman Antiquities edited by William Smith (1870) p.204