Nero, Lugdunum (Lyon) mint, 3rd emission, 65 AD.,
Æ Sestertius (34-35 mm / 25,12 g),
Obv.: NERO CLAVD CAESAR AVG GER P M TR P IMP P P , laureate head of Nero facing right, bigger globe at point of neck (RIC obv. type 31 B).
Rev.: PACE P R TERRA MAR[IQ P]ARTA I[A]NVM CLVSIT / S - C , the temple of Janus with latticed windows and garland hung across closed doors set on right.
RIC I, 177, 438 (common) ; BMC 319 ; WCN 419 ; Coh. 146 .
The temple of Janus, the Roman god of beginnings and endings, was one of Rome’s most ancient centers of worship. It was said that Romulus had built it after he made peace with the Sabines, and that it was king Numa who decreed that its doors should be opened during times of war and shut during times of peace. In all of Roman history until the reign of Nero, the temple doors had been shut perhaps five or six times  once under king Numa (who originated the tradition), once at the end of the Second Punic War, three times under Augustus, and, according to Ovid, once under Tiberius.
In 65 AD, when peace had been generally established in the Empire, Nero understandably requested the closing of the temple’s doors. He marked the event with great celebrations and trumpeted his pacific policy by issuing a large and impressive series of coins. The inscription on this issue announces “the doors of Janus have been closed after peace has been procured for the Roman People on the land and on the sea." The doors of the temple probably remained closed for less than a year, being opened again with the onset of strife in Judaea in 66.