The city of Rome at its height had a population of somewhere between half a million and a million people — the estimates vary and the ancient census figures are difficult to interpret — compressed into an urban area that had no master plan, no grid, and no effective building code until the fires that made such codes politically possible. The vast majority of these people lived not in the marble houses of imperial imagination but in multi-story apartment buildings called insulae — islands — so called because they filled city blocks the way islands fill water, surrounded on all sides by streets. The insula was Rome’s residential reality, and it was often dangerous, frequently squalid, and occasionally catastrophically flammable.

A museum case in Berlin’s Altes Museum holds a collection of Roman domestic bronzes from Rome and Pompeii, first through fourth century AD, under a label that states its subject with admirable directness: Luxury in the Roman house. The contents repay attention. Two griffins — mythological hybrids of eagle and lion, rendered with precise musculature — served as the decorative supports of a folding table, their bodies forming the legs, their wings providing the lateral bracing. A satyr and nymph group, extravagantly detailed, formed the foot of a large bronze vessel. Small bronze ducks and swans — the fulcra — decorated the scroll-ends of couches and dining beds, the curved terminals that distinguished a proper Roman reclining couch from mere functional furniture. Two portrait busts on red marble pedestals completed the ensemble. None of this was structural. All of it was mandatory, in the sense that a wealthy Roman household without this level of decorative investment was announcing, inadvertently, that its owner could not afford it.