The emperor was at length constrained, in view of new menaces from the Turks, to assent to the celebrated Treaty of Passau, on the 2d of August, 1552. The spirit of true toleration was then scarcely known in the world. After long debate, in which both parties were often at the point of grasping arms, it was agreed that the Protestants should enjoy the free exercise of their religion in the places specified by the Augsburg Confession. In all other places Protestant princes might prohibit the Catholic religion in their States, and Catholic princes might prohibit the Protestant religion; but in each case the expelled party were to be at liberty to sell their property, and to emigrate without molestation to some State where their religion was dominant. Even this wretched burlesque of toleration was so offensive to the pope, that he threatened to excommunicate the emperor and his brother Ferdinand if they did not immediately declare these decrees to be null and void throughout their dominions. Charles V. unquestionably inherited a taint of insanity. His mother, the unhappy Joanna, daughter of Isabella, Queen of Spain, after lingering for years in the most insupportable glooms of delirium, died on the 4th of April, 1555. Her imperial son had already become the victim of extreme despondency. Harassed by disappointments, mortified by reverses, and annoyed by the undutiful conduct of his son, he shut himself up in his room, refusing to see any company but his sister and servants, and rendering himself insupportable to them by his petulance and moroseness. For nine months he did not sign a paper. He was but fifty-five years of age, but was prematurely old, and the victim of many depressing diseases. There was probably not a more wretched man in all Europe than the Emperor Charles V. He resolved, by abdicating the throne, to escape from the cares which tortured him. The important ceremony took place with much funereal pomp on the 4th of April, 1555. The emperor had fixed upon the Convent of St. Justus, in Estremadura, Spain, as the place of his retreat. The massive pile was far removed from the busy scenes of the world, imbosomed among hills covered with wide-spread and gloomy forests, with a mountain rivulet murmuring by its walls. There is considerable diversity in the accounts transmitted to us of convent-life. According to the best evidence which can now be obtained, it was as follows:―― The emperor caused to be erected within the walls of the convent a small building, two stories high, with four rooms on each floor. These rooms, tapestried in mourning, were comfortably furnished. Choice paintings ornamented the walls, and the emperor was served from silver plate. Charles was not of a literary turn of mind, and a few devotional books constituted his only library. A pleasant garden, with a high enclosure which sheltered the recluse from all observation, invited the emperor to gravelled walks fringed with flowers.