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

[2] On his tenth birthday in 1916, Wilhelm was made a lieutenant in the 1st Guards Regiment, and was given the Order of the Black Eagle by his grandfather.

The former Crown Prince and his family remained in Potsdam, where Wilhelm and his younger brothers attended the local gymnasium.

Wilhelm's grandfather did not approve of the marriage of a member of the minor nobility with the heir apparent in line to the German throne.

In 1940[date missing], the ex-Emperor recognized the marriage as dynastic and the girls were accorded the style of Princesses of Prussia[10][verification needed] (although their father was not restored to his former place in the putative line of succession, his renounciation to his rights remaining valid): 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.

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

[2][13] 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.