In 1598 a man - branded the Calabrian Charlatan by his Spanish opponents - appeared in Venice claiming to be King Sebastian, the Portuguese monarch who disappeared in battle some twenty years before. Over the next five years Venetians, Spaniards, and Portuguese wrangled over the true character and identity of the man. Was he a lunatic? Was he an impostor? Was he a messianic king? Eric Olsen uses this strange event to explore Portuguese millenarianism and how a group of Portuguese rebels sought to exploit it to free their nation from Spain.