Platon a celebrated Russian prelate of modern times, whose family name was Beffschin, was born June 29, 1737. He was the son of a village priest near Moscow, in the university of which capital he received his education, and, besides studying the classical tongues, made considerable proficiency in the sciences. His talents soon caused him to be noticed, and, while yet a student in theology, he was appointed, in 1757, teacher of poetry at the Moscow academy, and in the following year teacher of rhetoric at the seminary of the St. Sergius Lawra, or convent. He shortly afterwards entered the Church, became successively hieromonach, prefect of the seminary, and, in 1762, rector and professor of theology. That same year was marked by an event in his life which greatly contributed to his advancement, for on the visit of Catharine II to the St. Sergius Lawra, after her coronation, he addressed the empress in an eloquent discourse, and on another occasion preached before her. So favorable was the impression he made, that he was forthwith appointed court preacher and preceptor in matters of religion to the grand-duke (afterwards the emperor Paul), for whose instruction he drew up his Orthodox Faith, or Outlines of Christian Theology, which is esteemed one of his best and most useful productions, and has been reproduced in English by Pinkerton (Lond. 1814), by Coray (1857), and by Potissaco (1858). During the four years of his residence at St. Petersburg, Platen frequently preached before the court, and also delivered on various occasions many of the discourses and orations which are among his printed works. After being created member of the synod at Moscow, by an imperial order, he was made archbishop of Twer in 1770. His attention to the duties of his new office was assiduous and exemplary; for he not only set about improving the course of study pursued in the various seminaries throughout his diocese, but established a number of minor schools for religious instruction, and drew up two separate treatises, one for the use of the teachers, and the other for their pupils. He was also entrusted with the charge of instructing the princess of Würtemberg, Maria Feodorowna, the grand-duke's consort, in the tenets and doctrines of the Graeco-Russian Church. At the beginning of 1775 he received the empress at Twer, and proceeded with her and the grand-duke to Moscow, where he was advanced to that see, with permission to retain the archimandriteship of the Sergius Lawra. With the exception of some intervals occasioned by his being summoned to St. Petersburg, where he preached before the court, it was in that convent that he chiefly resided, until he erected another in his vicinity at his own expense, in 1785, called the Bethania. Two years afterwards he was made metropolitan of the Russian Church, in which capacity he crowned the emperor Alexander, at Moscow, in 1801, delivering on that occasion a discourse that was translated into several modern languages, besides Latin and Greek. He died in his convent of Bethania, Nov. 11-23, 1812. His works, printed at different times, amount in all to twenty volumes, containing, besides various other pieces, 595 sermons, discourses, and orations, many of which are considered masterpieces of style and of eloquence. A selection from them, consisting of the finest passages and thoughts, was published in two volumes in 1805. — English Cyclop. s.v. See Mouravieff, Hist. of the Church of Russia (Oxf. 1842); Otto, Hist. of Russian Literature, p. 327-330; Hagenbach, Hist. of Christian Doctrines, 2, 459, 460; Schlegel, Kirchengesch. des 18ten Jahrh. 1, 59 sq.