The ancient Romans are well known for their love of the pageantry of power. No single ceremony better attests to this characteristic than the triumph, which celebrated the victory of a Roman commander through a grand ceremonial entrance into the city that ended in rites performed to Rome's chief tutelary deity, Jupiter Optimus Maximus, on the Capitoline hill. The triumph, however, was only one form of ceremonial arrival at the city, and Jupiter was not the only god to whom vows were made and subsequently fulfilled at the end of a successful assignment. Ushering in a New Republic...