Sebastianism in literature refers to a theme centered around the longing for a lost or idealized leader, often represented by the figure of King Sebastian of Portugal. This concept emerged from the historical context of his disappearance in the Battle of Alcácer Quibir in 1578, leading to a sense of hope and expectation among his followers that he would return to restore the nation. The theme is prevalent in various literary works, symbolizing the desire for redemption and renewal. Authors often use Sebastianism to explore ideas of identity, nationalism, and the impact of absence on society, reflecting broader human emotions related to loss and hope.