Prince William of Hesse-Kassel

He was titular Landgrave of Hesse-Kassel-(Rumpenheim) and for many years heir presumptive to the throne of Hesse-Kassel.

His father was himself a younger son of Frederick II, Landgrave of Hesse-Kassel and Princess Mary of Great Britain.

The castle served as a meeting place for the Hesse-Kassel-Rumpenheim branch for many years and gathered Danish, Hesse, British and other royal families.

Landgrave William took a keen interest in Danish affairs of state and in the succession issues in the 1840-ties.

Landgrave Wilhelm is the maternal grandfather of Queen Alexandra of the United Kingdom, King Frederick VIII of Denmark, King George I of Greece, Empress Maria Feodorovna of Russia, and Grand Duchess Adelheid of Luxembourg and paternal grandfather of Prince Frederick Charles of Hesse (elected King of Finland on 9 October 1918, but renounced the throne on 14 December 1918).

Gathering of royals in the castle of Rumpenheim (Including Landgrave Wilhelm (seated to the right in the picture), his grandson-in-law Albert Edward, Prince of Wales , later King Edward VII and his granddaughter Princess Alexandra of Wales , later Queen Alexandra), 1865)