At first, during the Ancient Roman Kingdom, and the Early Republic, the distinction of patricians and plebeians was more meaningful. Patricians were those who descended from noble families and had more wealth, while plebeians were everyone else.
However, as the Roman Republic expanded and progressed, many plebeians began to acquire wealth and political power.
By the mid-republic, there were landowners of both patrician and plebeian origin.
An anvil is something that is used to hammer metal into shape on. Von Billow meant that Germany would either be that which hammers the metal, or that which gets hammered on.