Queen Elizabeth II and Prince Philip reportedly both gave Prince William an ultimatum regarding his relationship with Kate Middleton.

The Duke and Duchess of Cambridge dated for almost a decade and had two major splits before Prince William popped the big question to Middleton. According to royal correspondent Camilla Tominey, the Queen and Duke of Edinburgh found their dating history too long.

“Now they are back together, the Queen wants William to do the right thing – either marry the girl or let her go,” Tominey wrote.

She added that Queen Elizabeth would prefer for them to break up for good than marry each other and end up getting divorced in five years' time.

“But if Kate is the one, then a five-year courtship is long enough,” Tominey added. “Prince Philip has told William he cannot keep stringing along Kate forever.”

Prince Charles reportedly also received an ultimatum from his father when he was dating Princess Diana. Initially, the Prince of Wales was “terrified of making a promise and living to regret it.” He and Princess Diana would appear together on social occasions only to find his ex-girlfriend Camilla Parker Bowles and her ex-husband, Andrew, in the same circle.

The Duke of Edinburgh urged Prince Charles to do a quick move and marry Princess Diana before her reputation was ruined. At the time, the Princess of Wales grew anxious about Camilla’s presence in Prince Charles’ life.

Prince Charles listened to his father’s advice and gave in to the pressure. Unfortunately, his marriage with Princess Diana didn’t work out. In 2005, he married Camilla.

Prince William was afraid to do the same mistake, so he decided to take his time and would not be pressured into the altar.

“He was reluctant to bow to similar pressure and vowed not to be hurried to the altar,” Katie Nicholl wrote in her book “The Making of a Royal Romance.

In 2004, there were rumors that Prince William would propose to Middleton. He squashed the rumors saying that he was only 22 and had no plans to get married until he is at least 28 or 30.  

True to it, when Prince William turned 28, he proposed to Middleton. The couple got engaged in 2010 and tied the knot in 2011.