Hugh Grosvenor, 7th Duke of Westminster is preparing to marry his bride, Olivia Henson, on 7 June, who will become the new Duchess of Westminster.
If the couple choose to have children in future, they could be affected by a centuries-old rule, which still favours male heirs when it comes to inheritance.
Most peerages only pass down the male line (known as male primogeniture), which means that the peerage can only be inherited by a male relative.
If the Duke and Duchess' firstborn child is a daughter, under the current laws, she will not be entitled to inherit the Westminster title and the family fortune and estate that goes with it. Instead, like Hugh's three sisters, any potential daughters would be styled as lady, while his eldest son would be known as Earl Grosvenor until he inherits the dukedom.
Such was the case with Hugh himself, who has two elder sisters, Lady Tamara and Lady Edwina Grosvenor. Instead, when their father, Gerald Grosvenor, 6th Duke of Westminster, died in 2016, the family title went to Hugh, his third child and only son.
Conservative MP Harriet Baldwin's proposed Hereditary Titles (Female Succession) Bill, which aims to change the law to allow female heirs to take a hereditary peerage or baronetcy, is due to be given a second reading on 21 June.
The Succession to the Crown Act (2013)
The Prince and Princess of Wales's daughter Princess Charlotte made history at the age of two as she became the first female royal to benefit from the change of succession law.
The Succession to the Crown Act (2013) amended the provisions of the Bill of Rights and the Act of Settlement to end the system of male primogeniture, under which a younger son can displace an elder daughter in the line of succession.
The law was updated ahead of Prince George's birth in 2013 to allow a possible firstborn daughter of Prince William and Kate to take precedence over any younger brothers. The decision was unanimously approved at a Commonwealth summit in Australia back in 2011, changing a 300-year rule.
While their firstborn was a son and their second child, a daughter, it meant that when Prince Louis was born in 2018, Charlotte retained her place in line to the throne.
The Act applies only to those born after 28 October 2011 so unfortunately Lady Louise Windsor, born in 2003, is still behind her younger brother, James, Earl of Wessex.
Male-preference primogeniture still exists in countries such as Monaco and Spain.