JOHANN, the popular name of JOHANN PHILIPSON, received from Sleids, near Cologne, where he was born in 1506. Passing from the gymnasium of his native town, he studied successively at Liège, Cologne, Louvain, Paris, and Orleans. The main drift of his studies had been directed to the law, but disliking the practice of the bar, he had allowed a considerable share of his attention to be drawn into classical channels. He had an opportunity of distinguishing himself in 1535, at the diet of Haguenau, and at the diet of Ratisbon, whether he had been induced to proceed by the recommendations of the French minister, Cardinal de Bellay, and by Francis I. of France. Sleidan did not remain long, however, under royal patronage. Having secretly adopted the Lutheran doctrines, he was compelled to quit the service of the first Francis in 1542. Retiring to Strasburg, he was appointed by the Protestant princes historian of the league of Schmalkald, and subsequently he was made professor of law by the council of that town. In 1545 he was employed in Starwick negotiations with France and England. While residing in the latter country he married an Englishwoman. On his return to Strasburg, he was sent as a deputy in 1551 to the council of Trent. On the dissolution of this assembly in 1552, Sleidan returned to Strasburg, where he enjoyed a pension which had been settled on him some time previously, and engaged in various politico-religious negotiations. Sleidan is now chiefly remembered by his faithful and accurate work, which has been lauded more than once, both by friend and foe, and which was first published in 1555. It is written in a style of simple and elegant Latinity, and has been the source whence historians and churchmen have drawn the materials of their remarks on the Reformation in Germany since his time. The addition of a book found among Sleidan's papers, after his death, augments the work to twenty-six books in all, and comprises the period from 1517 till 1556. It bears the title of Commentarii de Statu Religiosis et Republica Caroli V. The best edition is that of Böhm, Frankfurt, 3 vols., 1785–86. The work quickly appeared in German, Italian, French, and English. There have been two English versions of it, one in 1560 by John Daws, another in 1689 by G. Bohum. Sleidan's other works were his De Quatuor Summis Imperiis, 1556; Froissart's Chronicles in Latin, 1611; the Memoirs of Philip de Commines in Latin, 1548; and his Opuscula, which appeared in 1608. The death of his wife in 1555 plunged Sleidan into an abyss of melancholy, from which he was only delivered by death on the 31st December, 1556.