John Frederick I. Johann Frederick I, called Johann the Magnanimous, was Elector of Saxony and head of the Schmalkaldic League.
Johann Frederick was the eldest son of Elector Johann by his first wife, Sophie of Mecklenburg-Schwerin. His mother died fourteen days after his birth, on 12 July 1503.
He received his education from George Spalatin, whom he highly esteemed during his whole life. Spalatin was Martin Luther's friend and advisor and thus, through Spalatin's schooling, Johann developed a devotion to the teachings of Martin Luther.
His knowledge of history was comprehensive, and his library, which extended over all sciences, was one of the largest in Germany. He cultivated a personal relationship with Martin Luther, beginning to correspond with him in the days when the bull of excommunication was first issued against the Reformer, and showing himself a convinced adherent of Luther.
He carefully observed the development of the reformatory movement. He read Luther's writings, urged the printing of the first complete edition of his works, and in the latter years of his life promoted the compilation of the Jena edition. At the Elector castle at Torgau, he constructed a chapel specifically designed to be a Lutheran place of worship and invited Martin Luther to deliver the inaugural sermon. The influence of Lutheranism at Johann Frederick's court is visible also in the translation by Veit Warbeck