John Casimir, Duke of Saxe-Coburg (12 June 1564, Gotha – 16 July 1633, Coburg) John Ernest, Duke of Saxe-Eisenach (9 July 1566, Gotha – 23 October 1638, Eisenach) Succession. Later, the Emperor used the two surviving sons of John Frederick II against their uncle John William; in 1572 the Division of Erfurt was made.
While captured by the English, John II, Duke of Alençon had sold his fiefdom of Fougères to John V in order to raise the ransom for his release. After Alençon's release, his attempts to recover his territories led to conflict. John surrounded Alençon's fortress during the Siege of Pouancé (1432).