According to Roman tradition, the Temple of Jupiter Optimus Maximus (depicted), the most important temple in ancient Rome, was dedicated. Temple of Jupiter Optimus Maximus: The Temple of Jupiter Optimus Maximus, also known as the Temple of Jupiter Capitolinus, was the most important temple in Ancient Rome, located on the Capitoline Hill. It was surrounded by the Area Capitolina, a precinct where numerous shrines, altars, statues and victory trophies were displayed. September 13, 509 BC. Wiki link