When apprised of the matter, Wilhelm's father King Gustav V had no choice but to acquiesce with his daughter-in-law's wish, which was perfectly valid in law, and ordered that the imperial style be used invariably for Maria.

Maria sought a divorce because of what she described as the horror she then felt toward the Swedish royal family, due to their unlimited support of their official physician, Axel Munthe, who had accosted her sexually.

One of his rare forays into the political sphere happened during the Second World War, following the murder of the Danish playwright and Lutheran pastor Kaj Munk on 4 January 1944.

It was alleged, perhaps correctly, that the occupying German forces (specifically the Gestapo) were behind the murder, and the Danish resistance newspaper De frie Danske carried condemnatory reactions from numerous influential Scandinavians.

[5] Wilhelm suffered from emphysema caused by several years of chain smoking and died in his sleep, from a heart attack, in Flen, just 12 days before his 81st birthday.