When did they first believe in Hercules?

The belief in Hercules, a hero from ancient Greek mythology, dates back to at least the 12th century BCE. He is mentioned in Homer's "Iliad," which was composed in the 8th century BCE, indicating that his legends were already well-established by that time. Hercules' stories, including his Twelve Labors, became central to Greek culture and were later incorporated into Roman mythology as well.