Lord Palmerston is said to have declared that only one man in Europe knew all the history and details of the Sleswig-Holstein Question, and that his opinion about it seemed to be contrary to common sense. Since 1846 the problem had engaged the subtlest of European diplomatists and Jurisconsults in chronic controversy. The Kings of Denmark were also Sovereign Dukes of Sleswig-Holstein, and when they were absolute monarchs, the Germans in the Duchies were on the same footing as the Danes. They were equally in bondage. On the death of Frederick VI., in 1839, his great-nephew, Christian VIII., succeeded him as King of Denmark, and all the subsequent trouble rose from the fact that his only son, the Prince Frederick, was not likely to have an heir. The question of the succession was further complicated because the Salic Law which existed in the German Empire obtained in the Duchies of Sleswig and in Holstein--the latter, indeed, being actually one of the States of the Germanic Confederation. The Landgravine Louise of Hesse would, on the death of Prince Frederick, be the nearest heir to the Danish throne. But as the Salic Law excluded a woman from the Sovereignty of the Duchies, her succession must destroy the integrity of Denmark. It was of the utmost importance to Russia to preserve this integrity, because, in the first place, the Romanoffs had themselves claims to part of the Duchies, which, on the extinction of the Royal House of Denmark, might be extended over the whole country; and, in the second place, if the Duchies broke away from Denmark they would naturally be absorbed by Germany, which would thus gain not only a valuable seaboard, but the formidable naval station of Kiel, from which she might dispute Russian supremacy in the Baltic. Two leading ideas, therefore, are from this point seen to dominate diplomacy in treating the question of the Duchies. The first is the Teutonic idea, which was, by every legitimate means, to prevent the Duchies from being absorbed by Denmark, and to draw closer and closer their connection with Germany. The [Illustration: FREDERICK CHARLES, DUKE OF AUGUSTENBURG.]