Queen Elizabeth reportedly gave Prince William an ultimatum before he married Kate Middleton.

In an article for Sunday Express in 2006, the Queen reportedly issued a warning to Prince William by reminding her grandson that she will no longer accept royal divorces during her reign.

During the earlier generations, the royal family was plagued with countless divorces. For instance, Princess Margaret, Princess Anne, Prince Charles, and Prince Andrew are all divorced.

As such, when Prince William expressed his desire to tie the knot with Middleton, the Queen reminded him that enough is enough when it comes to divorce. As such, he needs to make sure that Middleton is the person that he wants to spend the rest of his life with.

The source said that the Queen's upbringing has taught her the importance of staying in one's marriage even in the face of adversity. The Queen's views are mostly inspired by her mother, who was gravely affected by the scandalous relationship between King Edward and Wallis Simpson.

"Both Princes William and Harry have been in no doubt that when they marry, it’s for keeps,” the source said.

By the looks of it, Prince William listened carefully to the Queen’s ultimatum. After dating Middleton for a decade, he finally proposed to her in 2010. Prince William reportedly got down on one knee during their vacation in Kenya.

Following their engagement, the royal couple sat down for an interview with the BBC. Prince William said that he wanted his proposal to really mean something. He also said that Kenya was the perfect place for the proposal.

Prince William and Middleton just celebrated their ninth wedding anniversary last month. And it seems that their marriage is really for keeps. The Duke and Duchess of Cambridge have also been blessed with three children, Prince George, 7, Princess Charlotte, 5, and Prince Louis, 2.

Meanwhile, Prince William also made headlines this week after it was revealed that he and Prince Harry are in touch.

While speaking with Entertainment Tonight, royal author Katie Nicholl revealed that the royal siblings have been talking on the phone. They have also been FaceTiming each other.

Since the royal siblings are self-quarantining separately, they have celebrated birthdays virtually. Nicholl also said that Prince Charles' previous diagnosis forced Prince William and Prince Harry to get in touch.