Philipp, Prince and Landgrave of Hesse (6 November 1896 – 25 October 1980) was head of the Electoral House of Hesse from 1940 to 1980. He joined the Nazi Party in 1930, and, when they gained power with the appointment of Adolf Hitler as Chancellor in 1933, he became Oberpräsident of the Prussian Province of Hesse-Nassau .
Donatus, Prince and Landgrave of Hesse (Heinrich Donatus Philipp Umberto; born 17 October 1966) is the head of the House of Brabant and the German House of Hesse. He is the eldest son and successor of German aristocrat Moritz, Landgrave of Hesse , and his former wife, Princess Tatiana of Sayn-Wittgenstein-Berleburg. 
On the other side stood their energetic opponent, the young Landgrave Philip I ‘the Magnanimous’ of Hesse. He had an advantage because Hesse had gained control of the entire disputed territory, which gave him a strong position over the small County of Nassau ; in addition, powerful imperial princes, such as Elector Frederick III ʻthe Wiseʼ of Saxony , were on his side as allies.