Henty's biography of the famous Swedish leader is a must-read for those interested in learning about one of history's most effective military commanders. From the preface: "The story of the Thirty Years' War is too long to be treated in one volume. Fortunately it divides itself naturally into two parts. The first begins with the entry of Sweden, under her chivalrous monarch Gustavus Adolphus, upon the struggle, and terminates with his death and that of his great rival Wallenstein. This portion of the war has been treated in the present story. The second period begins at the point when France assumed the leading part in the struggle, and concluded with the peace which secured liberty of conscience to the Protestants of Germany. This period I hope to treat some day in another story, so that you may have a complete picture of the war. The military events of the present tale, the battles, sieges, and operations, are all taken from the best authorities, while for the account of the special doings of Mackay's, afterwards Munro's Scottish Regiment, I am indebted to Mr. J. Grant's Life of Sir John Hepburn."