Sleidan, John, an excellent German historian, was born in 1506, at Sleiden, a small town upon the confines of the duchy of Juliers, whence he derived his name. His origin, according to Varillas, was so obscure, that not knowing the name of his father, he adopted that of his birth-place; but this is the report of an enemy, as his father’s name was Philip, and his family not of the lower order.
He went through his first studies in his own country, together with the learned John Sturmius, who was born in the same town with himself; and afterwards removed, first to Paris, and then to Orleans, where he studied the law for three years. He took the degree of licentiate in this faculty; but, having always an aversion to the bar, he continued his pursuits chiefly in polite literature.
Upon his return to Paris, he was recommended by his friend Sturmius, in 1535, to John Du Bellay, archbishop and cardinal; who conceived such an affection for him, that he settled on him a pension, and communicated to him affairs of the greatest importance; for Sleidan had a turn for business, as well as letters. He accompanied the ambassador of France to the diet of Haguenau, but returned to Paris, and remained there till it was not safe for him to stay any longer, as he was inclined to the sentiments of the reformers.
In 1542 he retired to Strasburg, where he acquired the esteem and friendship of the most considerable persons, and especially of James Sturmius; by whose counsel he undertook, and by whose assistance he was enabled, to write the history of his own time. He was employed in some negociations both to France and England; and, in one of these journeys, he met with a lady whom he married in 1546. About the same time the princes of the league of Smalcald honoured him with the title of their historiographer, and granted him a pension, and when he lost this by the dissolution of the league in 1547, the republic of Strasburgh gave him another. In 1551, he went, on the part of the republic, to the council of Trent; but, the troops of Maurice, elector of Saxony, obliging that council to break up, he returned to Strasburgh without having transacted any business.
He was employed in other affairs of state, when the death of his wife, in 1555, plunged him into a deep melancholy, with such a total loss of memory, as that he did not know his own children. Some imputed this to poison; and others to natural causes. It ended, however, in his death, at Strasburg, Oct. 31, 1556, in the fiftieth year of his age.
He was a learned man, and an excellent writer. In 1555, came out in folio, his De statu Religionis & Reipublicæ, Carolo Quinto Cæsare, Commentarii, in twenty-five books, from 1517, when Luther began to preach, to 1555. This history was quickly translated into almost all the languages of Europe, and has been generally thought to be well and faithfully written, notwithstanding the attempts of Varillas and other popish authors to discredit it. It did not stand solely upon Sleidan’s own authority, which, however, must be of great weight, considering that he wrote of times in which he lived, and of transactions in which he had some concern; but was extracted from public acts and original records, which were in the archives of the town of Strasburg, and with which he was furnished by James Sturmius. Besides this history, which is his principal work, he wrote De quator summis Imperiis libri tres, a compendious chronological account of the four great empires, which, on account of its singular utility, has been often printed. He epitomized and translated into Latin the Histories of Froissart and Philip de Comines, and was the author of some other works relating to history and politics, the principal of which are printed in a volume of Opuscula, Hanover, 1608, 8vo.1