Kate Middleton
Kate Middleton will inherit Princess Diana's title. Pictured: Middleton and Camilla head back along the Mall to Buckingham Palace during Trooping The Colour on June 9, 2018 in London. Getty Images/Chris Jackson

Kate Middleton will be the next Princess of Wales.

The title Princess of Wales is strongly associated with Princess Diana. But the honor is actually given to the second-in-line to the throne. Since Prince William is the next successor, he is the Prince of Wales and technically his wife is the Princess of Wales, Francesca Specter, lifestyle journalist of Daily Express reported.

Camilla Parker Bowles could actually use the same title as he is the wife of the Prince of Wales, but she refused out of respect for the late, Princess Diana. When Prince Charles takes over the reign, Prince William will be the new Prince of Wales and Middleton will be the new Princess of Wales.

Specter noted that the Duchess of Cambridge and Duchess of Sussex will never be a princess in their own right. They only receive the titles due to their husbands.

In related news, the Duke and Duchess of Cambridge are reportedly required to follow an unwritten royal protocol when traveling. Prince William and Middleton should not travel with their children, especially Prince George abroad. This is to protect the succession of throne because their 4-year-old son is the third-in-line to the throne.

Prince William and Middleton should not board the same plane so that in case of emergency, when the plane crash, the line of succession would not be affected. However, the Duke and Duchess of Cambridge already broke it when they took Prince George along in their trip to Canada, Australia and New Zealand.

According to an insider, Prince William asked Queen Elizabeth II's permission for the said trip. Since the said travel rule was not official, "it is something that the Queen has the final say on." The Queen apparently allowed the royal couple to take their son along.

Meanwhile, Prince Harry and Markle don't necessarily need to follow the same rule as the duke is only sixth-in-line to the throne. So the Duke and Duchess of Sussex are free to travel with their future children together and board on the same plane.

In related news, Prince William has just arrived in Jordan. According to him, his wife, Middleton, who is still on maternity leave, was very upset that she couldn't accompany him on the said trip.