Watch List notes:

Nero. A.D. 54-68. AE sestertius (34.78 mm, 27.80 g, 7 h). Lugdunum mint, struck A.D. 65. IMP NERO CAESAR AVG PONT MAX TR POT P P, laureate head left, globe at point of neck / S-C, triumphal arch surmounted by quadriga, statue of Mars between columns. RIC 432; BMCRE 329. aVF. 

From the D. Thomas Collection. 

This triumphal arch was erected by Nero to commemorate his military victories against the Parthians in Mesopotamia and Armenia. The result of these battles was a peace treaty that was honored for nearly 50 years.