"The Fortress," a 2017 film, is based on the historical event of the siege of Namhansanseong fortress in 1636 during the Joseon Dynasty. The movie depicts the final king of independent Joseon, Injo (modern day Korea), facing an invasion by the Qing dynasty and his retreat to the fortress to protect his people. While the movie draws on real events and historical figures, it also incorporates fictional elements and dramatic liberties to tell a story. The film follows the king's council and their divided opinions on how to handle the situation, adding a layer of political drama to the historical context.