Prince Wilhelm of Prussia (1906–1940)

Prince Wilhelm of Prussia (Wilhelm Friedrich Franz Joseph Christian Olaf, in English, William Frederick Francis Joseph Christian Olaf; 4 July 1906 – 26 May 1940) was the eldest child and son of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin. At his birth, he was second in line to the German throne, and was expected to one day succeed to the throne after the deaths of his father and grandfather, both of whom ultimately outlived him.

Early life and childhood
Wilhelm was born on 4 July 1906 at the Hohenzollern family's private summer residence, Marmorpalais, or Marble Palace, near Potsdam, where his parents were residing until their own home, Schloss Cecilienhof, could be completed. His father was Crown Prince Wilhelm, the eldest son and heir to the German Emperor, Wilhelm II. His mother was Duchess Cecilie of Mecklenburg-Schwerin. Emperor Franz Joseph of Austria was one of the Prince's godfathers.

The selection of a nanny for Wilhelm and his younger brother, Louis Ferdinand (born in 1907) caused considerable distress within the family.

On his tenth birthday in 1916, Wilhelm was created a lieutenant in the 1st Guards Regiment, and was given the Order of the Black Eagle by his grandfather. Two years later, when he was only twelve, the German monarchy was abolished. Wilhelm and his family remained in Germany, though his grandfather, the former Emperor, went into exile in the Netherlands. The former Crown Prince and his family remained in Potsdam, where Wilhelm and his younger brothers attended the local gymnasium. After graduating from secondary school, Wilhelm went on to study at the Universities of Königsberg, Munich and Bonn. In 1926, while a student at the University of Bonn, Wilhelm joined the Borussia Corps, a student organization of which his father, grandfather, and other members of the Prussia Royal Family were members.

Marriage and children
While a student at Bonn, Wilhelm fell in love with a fellow student, Dorothea von Salviati (10 September 1907-7 May 1972). His grandfather did not approve of the marriage of a member of the minor nobility with the second in line to the German Throne. At the time, the former Kaiser still believed in the possibility of a Hohenzollern restoration, and he would not permit his grandson to make an unequal marriage. Wilhelm told his grandson: "Remember, there is every possible form of horse. We are thoroughbreds, however, and when we conclude a marriage such as with Fräulein von Salviati, it produces mongrels, and that cannot be allowed to happen."

However, Wilhelm was determined to marry Dorothea. He renounced any rights to the succession for himself and his future children in 1933. Wilhelm and Dorothea married on 3 June 1933 in Bonn. They had two daughters. In 1940, the marriage was recognised as dynastic and the girls were given the title and style of Princesses of Prussia.
 * HRH Princess Felicitas Cecilie Alexandrine Helene Dorothea of Prussia, (7 June 1934–1 August 2009), was fifth in the line of first-born children that started with Queen Victoria's eldest child, Victoria, Princess Royal. This line has continued with Felicitas' own eldest daughter, Friederike von der Osten, and her daughter, Felicitas von Reiche.
 * HRH Princess Christa Friederike Alexandrine Viktoria of Prussia, born 31 October 1936 at Schloß Klein-Obisch, near Głogów

Military services
During the Weimar Republic, Wilhelm inadvertently caused a public scandal by attending Army manoeuvres in the uniform of the old Imperial First Foot Guards without first seeking government approval. The commander of the Reichswehr, Hans von Seeckt, was forced to resign as a result.

At the beginning of World War II, Wilhelm was among a number of Princes from the former Germany monarchies who enlisted to serve in the Wehrmacht, the unified armed forces of Germany.

Death and reaction
In May 1940, Wilhelm took part in the invasion of France. He was wounded during the fighting in Valenciennes and died in a field hospital in Nivelles on 26 May 1940. His funeral service was held at the Church of Peace, and he was buried in the Hohenzollern family mausoleum in the Antique Temple in Sanssouci Park. The service drew over 50,000 mourners.

His death and the ensuing sympathy of the German public toward a member of the former German royal house greatly bothered Hitler, and he began to see the Hohenzollerns as a threat to his power. Shortly after Wilhelm's death, a decree known as the Prinzenerlass, or Prince's Decree, was issued, barring all members of the former German royal houses from service in the military.