Princess Charlotte looks out of the airplane window at Tegel airport in Berlin, Germany, July 19, 2017.
Princess Charlotte looks out of the airplane window at Tegel airport in Berlin, Germany, July 19, 2017. Reuters/Fabrizio Bensch

When her new sibling is born any time this month, Princess Charlotte will make history as the only female heir to the UK throne who won’t be bumped down by the arrival of a male heir. The removal of the male bias law now allows her to retain her position as the fourth in line to the throne.

Charlotte and her older brother, Prince George, are going to welcome their sibling when their mum, Kate Middleton, gives birth this month. In the past, if the Duchess of Cambridge’s third child turned out to be a boy, Charlotte would have been bumped to fifth in the line of succession, while her new brother would take her place as fourth. But thanks to the Succession to the Crown Act 2013, she will retain her position in the succession line regardless if she had a brother or a sister.

“Succession to the Crown not to depend on gender: In determining the succession to the Crown, the gender of a person born after 28 October 2011 does not give that person, or that person’s descendants, precedence over any other person (whenever born),” the act reads. That means Kate and Prince William’s next child will not take precedence over Charlotte, who was born in 2015.

Her great-aunt, Anne, Princess Royal, wasn’t so lucky. At the time of Anne’s birth, she was third in line to the British throne, behind her mother, Queen Elizabeth, who was still a princess in 1950, and her elder brother, Prince Charles. But when Prince Andrew was born in 1960, she was bumped down to fourth.

The Succession to the Crown Act of the United Kingdom came into effect in March 2015 but was rushed through Parliament in 2013 when Kate was pregnant with her first child. It was rushed to make Kate and William’s first child the future monarch in case the child turned out to be a girl. As it happened, the couple gave birth to a boy they named George.

The Act also removed the disqualification of a successor to the throne if he or she married a Catholic. Prince Michael of Kent, Queen Elizabeth’s cousin, was removed from the succession line in 1978 when he married his wife, née Baroness Marie Christine von Reibnitz, who is Catholic. He is now back in line at 45th.

Another change to the law is the number of people who need the Queen’s consent to marry. Before, all descendants of George II needed to obtain the permission of the Sovereign to marry. Now, only the first six people in the line of succession must acquire Her Majesty’s permission.

Prince Harry, who is currently sixth in line, obtained his grandmother’s consent to marry Meghan Markle last month.