On the night of 25 September 1829, the jewels of the Princess of Orange disappeared from her palace in Brussels. Suspicion quickly fell on her husband, Prince Willem of Orange, a Waterloo veteran known to be deeply in debt. But when the police failed to find any witnesses or leads, the investigation ground to a halt. In 1831, Anna Pavlovna’s jewels surfaced in New York in the hands of a former Napoleonic deserter named Constant Polari. Dutch officials scrambled to reclaim the jewels and extradite Polari, hoping a public trial would clear their prince’s name. But President Andrew Jackson’s customs collector preferred to confiscate the jewels, sell them, and pocket his share of the proceeds. When Polari’s lover dug up a buried portion of the gems and sailed for Europe, it triggered a race across the Atlantic, a kidnapping from Bellevue prison, and a sensational trial with a last-minute twist. True crime meets royal history in this long-forgotten caper that pitted the old world’s diplomacy against the new world’s self-determinism. Drawing on previously neglected case documents and sources in five languages, the tale of Anna Pavlovna’s stolen jewels unfolds against a backdrop of war, revolution, corruption, and betrayal.