William IV, Landgrave of Hesse-Kassel

William IV of Hesse-Kassel (24 June 153225 August 1592), also called William the Wise, was the first Landgrave of the Landgraviate of Hesse-Kassel (or Hesse-Cassel). He was the founder of the oldest line, which survives to this day.

Life

Landgrave William was born in Kassel, the eldest son of Landgrave Philip the Magnanimous and Christine of Saxony. After his father's death in 1567, the Landgraviate of Hesse was divided among the four sons from the late Landgrave of Hesse's first marriage, and William received the portion around the capital Kassel, the Landgraviate of Hesse-Kassel.

William took a leading part in safeguarding the Lutheran Reformation, and was indefatigable in his endeavours to unite the different sections of Protestantism against Catholicism. However, he was reluctant to use military force in this conflict.

As an administrator he displayed rare energy, issuing numerous ordinances, appointing expert officials, and in particular ordering his slender finances. By a law of primogeniture he secured his Landgraviate's land against such testamentary divisions as had diminished his father's estate.

William was a pioneer in astronomical research, and perhaps owes his most lasting fame to his discoveries in this branch of study. Most of the mechanical contrivances which made instruments of Tycho Brahe so superior to those of his contemporaries were adopted in Kassel about 1584. From then on, the observations made in Hesse-Kassel seem to have been about as accurate as those of Tycho. However, the resulting longitudes were 6' too great in consequence of the adopted solar parallax of 3'. William also collected botanical books, including those by Dodanus, Lobelius and Clusius.

Family and children

William was married to Sabine of Württemberg, daughter of Christoph, Duke of Württemberg. They had the following children: Anna Maria of Hesse-Kassel (27 January 156721 November 1626), married on 8 June 1589 to Louis II, Count of Nassau-Weilburg Hedwig of Hesse-Kassel (30 June 15697 July 1644), married on 11 September 1597 to Ernst of Schaumburg Agnes of Hesse-Kassel (30 June 15695 September 1569) Sofie of Hesse-Kassel (10 June 157118 January 1616) Maurice, Landgrave of Hesse-Kassel (25 May 157215 March 1632), succeeded as landgrave on William IV's death in 1592. Sabine of Hesse-Kassel (12 May 157329 November 1573) Sidonie of Hesse-Kassel (29 June 15744 April 1575) Christian of Hesse-Kassel (14 October 15759 November 1578) Elisabeth of Hesse-Kassel (11 May 157725 November 1578) Christine (19 October 157819 August 1658), married on 14 May 1598 to John Ernst, Duke of Saxe-Eisenach Juliane, born and died 9 February 1581

In addition William had a few illegitimate children. Most significant and favored among these was Philipp von Cornberg (1553–1616), William's son by Elisabeth Wallenstein. Philipp was ennobled by his father and became the ancestor of the current Barons von Cornberg.

Ancestry