Antoninus Pius, 138-161. As (Copper, 26 mm, 12.05 g, 12 h), Rome, 143. ANTONINVS AVG PIVS P P TR P COS III Laureate head of Antoninus Pius to right. Rev. IMPERATOR•II / ANCILIA / S - C Two oval shields (ancilia), decorated with thunderbolts and with rounded projections above and below. BMC 1630. Cohen 30. RIC 736a. A lovely example with an excellent reverse. Somewhat smoothed, otherwise, good very fine.

The reverse of this wonderful as depicts two of the twelve sacred shields known collectively as the ancilia, which were kept in the Temple of Mars in Rome. According to legend, Jupiter cast a divine shield from the sky during the reign of Numa Pompilius, Rome's second king. It was accompanied by a voice proclaiming that Rome would rule the world as long as the shield existed. To deter thieves, Numa had eleven additional shields made that exactly copied the original. Each year in the month of March, the month of Mars, they were taken out and paraded through the streets of Rome by the Salii, a group of twelve priests who donned archaic armor and danced to the beat of their shields with staves, singing the Carmen Saliare, a sacred hymn to the gods for the protection of Rome.