The last action in the novel is based on a real action, the Battle of Cape Santa Maria in October 1804, in which four British frigates – HMS "Indefatigable", HMS "Lively", HMS "Medusa" and HMS "Amphion" – successfully intercepted a Spanish flotilla carrying gold from South America, leaving from the mouth of the River Plate in present-day Montevideo, Uruguay. Captain Hamond, later Sir Graham Hamond, 2nd Baronet, was not in fact a member of Parliament and was in command of "Lively" in the action, taking the Spanish ships as Aubrey does in the novel.