As - Trajan S P Q R OPTIMO PRINCIPI S C

Trajan's "Optimus Princeps" title — formally voted him by the Senate in 114 AD, though already in informal use by around 103 — makes this one of the few Roman coin series where the obverse legend itself records an active honorific rather than a standard imperial titulature. The Senate's decision to institutionalize the title was without precedent; no emperor before or after received it officially during his lifetime.

RIC II 555 places this issue within Trajan's third to fifth emission, a period of intense mint activity coinciding with the Dacian wars and their aftermath.