A fragile glass vessel survives the fall of Rome, wars, plagues, and Renaissance popes, only to be smashed in the British Museum in 1845 by a drunk university student who picked up a nearby sculpture and threw it. This episode traces the full life cycle of the Portland Vase, the most famous piece of Roman cameo glass in existence. We start with how it was made in the early empire, only decades after glassblowing itself was invented: a bubble of molten blue glass dipped into molten white, cooled without tearing apart despite different thermal expansion rates, then carved by a gem cutter over what was likely two years of labor.

The carved scenes have never been decoded with certainty. We walk through the mythological readings, including the marriage of Peleus and Thetis, and the political theory that the vase was propaganda for Octavian, with the snake representing the rumor that Apollo fathered him. Then we follow the vase from a sarcophagus near Rome to the Barberini family, to the Duchess of Portland, and into the hands of Josiah Wedgwood, whose four-year struggle to replicate it in Jasperware produced both a sensation and a permanent record of the intact design. Finally we cover the 1845 destruction, the legal loophole that left the vandal fined only three pounds for the display case, and three restorations spanning more than a century.

• The dip overlay process and why matching two glass chemistries was a life-or-death step for the object
• Fringe theories, from a molded powder overlay to the claim that the vase is a 16th-century fake
• The Duke of Portland’s decision not to sue an impoverished family for an act of folly
• The 37 leftover fragments that sat forgotten in a box maker’s shop until 1948
• How animal glue yellowed and failed, and how epoxy resin and a BBC-filmed restoration made the vase whole again