Duchess Meghan will carry out three official public engagements with Queen Elizabeth in one day, marking the first time the new royal will be seen in public with Her Majesty, alone.
This means any daughters they might have will not inherit the Dukedom, and the title will die out completely if Harry and Meghan only have girls.
The rules came under celebrity scrutiny previous year when Downton Abbey creator Julian Fellowes, himself holding the title Baron of West Stafford since 2011, criticised the lack of change when the title of Baron Braybrooke passed to a distant cousin after his death, bypassing all eight of his daughters. It stated that the next king or queen of the United Kingdom will be determined by birth order, rather than by gender.
Corey and Meghan dated for two years before they called it quits just before she met Prince Harry.
The titles, which the newlyweds received from the Queen on their wedding day, can only be passed on to a future son. In contrast, the Duchess of Cambridge didn't head on her first official engagement with the Queen until nearly a year after she and Prince William married.
According to the Royal Family's website, the pair will open the Mersey Gateway Bridge at Catalyst Science Discovery Centre on June 14.
Harry and Meghan began dating not long after her split with Corey. "One can't just brush them aside", he explained.
Meghan has been invited by the Queen to join her on their first official engagement as a duo next week.
It explains why Prince Harry and Meghan's future daughters won't inherit their titles.
Dressed in an Oscar de la Renta dress and coat, she was the only family member present to support Meghan at St George's Chapel in Windsor Castle.