The online translations rock!
Well, I think he means, that by arming himself with the Reich he only wants to protect the people. The lower portion of the coin reads: Das Reich erhalten den 16 November 1797. That means: The Reich (Empire) received on the 16th November 1797. I guess there is a single context behind those two lines. The syntax is horrible tho.
It could of course also mean all the things the person on the coin has around him. The glorious history of the holy roman empire (Roman helmet) and the past before that (Greek helmet, the rod of Asklepios, a Greek shield, a Lyre... The rest I cannot recognize). Maybe they had managed to create a connection between their family (or the Reich) and ancient Rome (through the Holy Roman Empire)/ Greece (Don't know how... Maybe over Aeneas, who fled to Rome. I think this connection had been used by the French at some point.) . I don't really know my way around Preussen and how they used history and mythology at the time.