The Emperor Frederick II. was one of the most extraordinary personages in history. He has found many biographers among Continental writers. Muratori, Giannone, Von Raumer, and Hofler have described his remarkable career either with national pride or with stern condemnation. But until Dean Milman wrote his history of Latin Christianity, a few lines in Gibbon and a few pages of Hallam contained all the information which could be obtained respecting him by the English reader. Since the Dean wrote, information from other sources has been obtained, which I now propose to bring before you. We see this remarkable man only indistinctly through the mists of calumny and prejudice. On account of his long contest with the popes, he has been assailed by Roman Catholic writers with vituperative epithets. I propose in the following paper to give an account of his life; to show whether or no Roman Catholic writers were justified in regarding him as a monster of iniquity; to describe his natural endowments and acquirements, and the services which he conferred on his country; and to bring before you that celebrated struggle with the popes which has affected the course of events in his own age, and through succeeding generations.