Background
He was a great-grandson of Philip I "the Magnanimous".
He was a great-grandson of Philip I "the Magnanimous".
Hence, Ernest is known as the ancestor of the Catholic Rotenburg Quarter, a group of junior lines of the House of Hesse. Ernst was the eleventh child of the second marriage of the Landgrave Maurice of Hesse-Kassel (1572–1632) with Countess Juliane of Nassau-Dillenburg (1587–1643). Landgrave Ernst married in 1647 in Frankfurt with Countess Maria Eleonore of Solms-Lich (1632–1689).
Two sons from this marriage outlived Ernest: William (1648–1725) and Charles (1649–1711).
Ernest was brought up as a Calvinist during the Thirty Years" War. He made his Grand Tour to France and Italy, and fought with Hesse-Kassel during the final years of the war, for example at the Battle of Nördlingen on 3 August 1645.
In 1647, the army of Landgravine Amalie Elisabeth reconquered Lower Katzenelnbogen and returned it to Hesse-Kassel. In 1649, Ernest came of age and received Lower Katzenelnbogen.
Hesse-Rheinfels was not considered sovereign: it remained under the sovereignty of Hesse-Kassel, as did the other parts of the Rotenburg Quarter.
Details of the relationship between Hesse-Rheinfels and Hesse-Kassel were laid down in a series of house treaties. Nevertheless, political and judicial disputes often arose between the two houses. Ernest chose Burg Rheinfels castle, above Saint Goar on the left bank of the Rhine, as his residence and extended the castle to an imposing fortress.
The new Landgrave held his official into Saint Goar on 30 March 1649.
The construction activities associated with the extension of his castle and the fact that many landgraviate authorities resided at Rheinfels, contributed significantly to the economic boom of Saint Goar, which had suffered severely from the Thirty Years" War. In 1654, a compromise was reached: the Treaty of Ravensburg allow Ernest to create three Catholic parishes in his landgraviate, in Saint Goar, Nastätten and Langen-Schwalbach.
He then called himself Ernest of Hesse-Rotenburg-Rheinfels. Ernest was very interested in religious matters.
He was also religiously tolerant.
In 1666, he had the Rheinfelsen Book of Hymns printed, which contained both Catholic and Lutheran and Reformed hymns. Ernest corresponded with the leading scholars of his time, such as Leibniz
Ernest died in 1693 and was buried, at his request, in the Pilgrimage Church in Bornhofen Monastery in Kamp-Bornhofen.
