Aureus - Trajan S P Q R OPTIMO PRINCIPI

The legend OPTIMO PRINCIPI — "to the best ruler" — was not a standard imperial honorific but a specific title voted to Trajan by the Senate in 114 AD, though it appears on coinage well before that formal grant, suggesting the title was in informal use during the Dacian war years. The S P Q R prefix, invoking the Senate and Roman People as the dedicating authority, was a deliberate archaism meant to echo Republican tradition at a moment when Trajan was consolidating military prestige through two brutal Dacian campaigns that ended in 106 AD with the destruction of Sarmizegetusa.

RIC II 209 falls within the issue associated with Trajan's extensive building program, financed directly by Dacian gold and silver looted after the campaigns — treasure Dio Cassius estimated at over half a million pounds of gold.