Prince Philipp and his brother Christoph , were members of the National Socialist ( Nazi ) party .
On 23 September 1925 , at Racconigi Castle , Mafalda married Prince Philipp of Hesse , Landgrave of Hesse - Kassel and grandson of German Emperor Frederick III .
Prince Philipp of Hesse and Prince 's brother Christoph , were members of the National Socialist ( Nazi ) party .
On 23 September 1925 , at Racconigi Castle , Mafalda married Prince Philipp of Hesse , Landgrave of Hesse - Kassel and grandson of German Emperor Frederick III .