The Sebastianist Movement is a historical and cultural phenomenon that emerged in Portugal during the late 16th century. It centers around the belief that King Sebastian of Portugal, who disappeared in the Battle of Alcácer Quibir in 1578, would return to reclaim his throne and restore the nation. This idea became a symbol of hope for many Portuguese, especially during times of political instability and foreign domination. The movement gained momentum in the 17th century, influencing literature, art, and popular culture. Supporters, known as Sebastianists, viewed the king's anticipated return as a means to revive Portugal's former glory and independence. The legend of Sebastian continues to resonate in Portuguese identity and folklore today.