At the time of her father's accession to the throne, only males could ascend the throne of Denmark. As her parents had no sons, it was assumed that her uncle Prince Knud would one day assume the throne. The popularity of Frederick IX and his daughters and the more prominent role of women in Danish life paved the way for a new Act of Succession in 1953 which permitted female succession to the throne following the principle of male-preference primogeniture, where a female can ascend to the throne if she has no brothers. Benedikte's elder sister Margrethe therefore became heir presumptive, and Princess Benedikte and Princess Anne-Marie became second and third in the line of succession.