Gustavus Adolphus and the Struggle of Protestantism for Existence is a historical book written by C.R.L. Fletcher in 1890. This book tells the story of Gustavus Adolphus, the King of Sweden, and his role in the struggle of Protestantism during the Thirty Years' War. The author explores the political and religious climate of Europe during the 17th century, and how Gustavus Adolphus played a crucial role in the survival of Protestantism against the...