Sebastianism
Sebastianism (Portuguese: Sebastianismo) is a Portuguese messianic myth, based on the belief that King Sebastian of Portugal, who disappeared in the 1578 battle of Alcácer Quibir, would reappear and rescue Portugal from some future crisis. The belief gained momentum after an interpretation by priest António Vieira of the second chapter of the Book of Daniel (Daniel 2) and the Book of Revelation.