Genoa’s Sacro Catino: The Green Glass Basin Called the Grail

One Grail candidate is not a cup at all. In the treasury of Genoa’s Cathedral of San Lorenzo, the Sacro Catino is a shallow, six-sided green basin. Its tradition identifies it with a dish used by Jesus at the Last Supper, demonstrating how the object sought by Grail stories can change shape. For centuries, its striking material was thought to be emerald. The museum identifies it as green glass cast in a hexagonal mold. That correction did not erase the object’s importance: it changed what could responsibly be said about its manufacture and value. The museum’s account associates its arrival in Genoa with Guglielmo Embriaco after the capture of Caesarea in 1101, while acknowledging uncertainty over the basin’s date. It also describes its removal to Paris under Napoleon and its later breakage, probably during the return journey. Those episodes belong to a documented and traditionally transmitted European history; they do not establish a continuous provenance from Jesus’s table. The treasury’s setting adds another layer. The collection occupies underground medieval rooms associated with the cathedral, adapted for museum use in the twentieth century. The old object, the religious identification and the later exhibition setting have separate histories. This pin marks the Cathedral of San Lorenzo and its treasury, not another Genoa museum that may have borrowed the basin for a past exhibition. The Sacro Catino belongs in this collection as an actual claimed relic. Its identification with the Last Supper remains a tradition rather than an authenticated conclusion.