Later, Knud's two sons, Ingolf and Christian, were stripped of their titles of prince and removed from the line of succession by the new law because they had married commoners without asking permission to their uncle.

Prince Knud was born on 27 July 1900 at his parents' country residence, the Sorgenfri Palace, located on the shores of the small river Mølleåen in Kongens Lyngby north of Copenhagen on the island of Zealand in Denmark, during the reign of his great-grandfather King Christian IX.

Since Frederik IX had fathered no sons and the Danish Act of Succession at the time followed the principle of agnatic primogeniture, Prince Knud became heir presumptive and first in line to succeed his brother as king.

The new law made Frederik IX's thirteen-year-old daughter Margrethe the new heir presumptive, placing her and her two sisters before Knud and his family in the line of succession.

[8] The expression was first used in an article by Bent Thorndahl in the Copenhagen newspaper Politiken to describe the November 24, 1958 premiere, at the Falkoner Center in Frederiksberg, of the ballet “Det Forsinkede Stævnemøde” (“The postponed rendezvous”).

The following year, Birgitte Reimer, at the theatrical revue known as Cirkusrevyen, performed a song,[9] written by Erik Leth to a tune by Sven Gyldmark, which immortalized Prince Knud, somewhat unfairly mocking him as supposedly being a dullard: “Så ta'r vi den en gang til for Prins Knud.” (“Now we'll do it one more time for Prince Knud.”)[10]