Maurice of Hesse-Kassel (; 25 May 1572 – 15 March 1632), also called Maurice the Learned or Moritz, was the Landgrave of Hesse-Kassel (or Hesse-Cassel) in the Holy Roman Empire from 1592 to 1627. Life Maurice was born in Kassel as the son of William IV, Landgrave of Hesse-Kassel, and of his wife Sabine of Württemberg. Although Maurice had been raised in the Lutheran faith, he converted to Calvinism in 1605. On the principle Cuius regio eius religio, Maurice's subjects were also required to convert to Calvinism. Maurice's conversion was controversial since the Peace of Augsburg had only settled religious matters betweens Roman Catholics and Lutherans and had not considered Calvinists. Maurice tried to introduce Calvinism to the lands which he had inherited from the extinct Hesse-Marburg branch of his family. Such a change of faith was contrary to the inheritance rules, and resulted in an ongoing conflict with the Hesse-Darmstadt branch. It also brought him into conflict with the Holy Roman Emperor, Matthias. English strolling players ('Die Englische Comoedianten') were frequent visitors to, and performers in, towns and cities in Germany and other European countries, including Kassel, during the 16th and 17th centuries. Landgraf Moritz (to use his German nomenclature) was a great supporter of the performing arts and even built the first permanent theatre in Germany, named the Ottoneum, in 1605. This building still exists today but as a Natural History Museum. Maurice's actions (though not necessarily the Ottoneum) ruined Hesse-Kassel financially. In 1627 he abdicated in favour of his son William V. Five years later he died in Eschwege. He was not only a serious musician but an expert composer (a Pavane of his, for the lute, has several times been recorded by both lutenists and guitarists). The leading musical figures whom he supported included Heinrich Schütz and John Dowland. Marriages and issue On 23 September 1593, Maurice married Agnes of Solms-Laubach (7 January 1578 – 23 November 1602). They had six children: Otto, Hereditary Prince of Hesse-Kassel (b. Kassel, 24 December 1594 – Hersfeld, 7 August 1617). Elisabeth (b. Kassel, 24 March 1596 – d. Güstrow, 16 December 1625), married John Albert II, Duke of Mecklenburg. Stillborn child (24 January 1597). Stillborn child (August 1599). Maurice (b. Kassel, 14 July 1600 – d. Kassel, 11 August 1612). William V, Landgrave of Hesse-Kassel (b. Kassel, 13 February 1602 – d. Leer, Ostfriesland, 21 September 1637). On 22