William VI of Hesse-Kassel was a German nobleman born on June 24, 1787. He was the last Landgrave of Hesse-Kassel, a territory in present-day Germany. William VI ruled from 1831 until 1866, overseeing a period of significant political and social change in his region. He was known for his efforts to modernize the administration and improve the economy. In 1866, during the Austro-Prussian War, Hesse-Kassel was annexed by the Kingdom of Prussia. Following this, William VI went into exile and lived in various European cities. He died on January 17, 1867, in Paris, France.