Domitian's Saecular Games were a major set-piece of his reign, celebrating them in AD 88, the 841st year after Rome was founded (Censorinus, On the Birthday 17). The Seacular Games had already been celebrated by both Augustus (in 17 BC) and Claudius (in AD 47).
Although meant to be celebrated once in a lifetime, the emperors could reinvent the calculations for the dating of the games in order to serve political and propagandic expediency.
The Reverse here shows Domitian sacrificing in front of a six-columned temple, with a flute-player and lyre-player in attendance, with the 'victimarius' marshalling a goat and a lamb. 
The coinage of the Ludi Saeculares mark a key oment in Domitianic coinage, as during Domitian's 14th consulship (September 88 - September 89) all denominations of Roman coinage were emblazoned with numismatic representations of the games.
