Sebastianism is a historical and cultural movement that originated in Portugal during the late 16th century. It is centered around the belief that King Sebastian of Portugal, who disappeared in the Battle of Alcácer Quibir in 1578, would one day return to reclaim his throne and restore the nation. This idea became a symbol of hope for many Portuguese people during times of political instability and foreign domination. The movement also reflects themes of messianism, where Sebastian is seen as a savior figure. Over time, Sebastianism influenced literature, art, and popular culture, contributing to a sense of national identity and longing for a better future in Portugal.