Queen Elizabeth II and Prince William
Queen Elizabeth II and Prince William chat to each other in the Royal Box at the Royal Albert Hall during the Annual Festival of Remembrance on Nov. 7, 2015 in London. Getty Images/Chris Jackson

Prince William broke an over century-old royal tradition, but Queen Elizabeth II was delighted.

Katie Nicholl explored Prince William’s unprecedented decision to study at St. Andrews in her 2010 book “William and Harry.” According to the royal biographer, the Duke of Cambridge’s decision broke a 150-year-old tradition.

“While the royal family have traditionally gone to Oxford or Cambridge, Prince William was set on breaking 150 years of tradition by going to Scotland’s oldest university,” Nicholl wrote.

Prince Charles, Prince Edward and King George VI had all attended Cambridge. However, the Prince of Wales was the only one among the three who graduated from the university.

According to Nicholl, Prince William’s decision to attend St. Andrews had something to do with his royal duties because he wanted to distance himself from it at the time.

“The four-year history of art course at St. Andrews, which is considered one of the best in the country, appealed to the prince, who wanted to postpone his royal engagements for as long as possible,” Nicholl continued.

Surprisingly, the Queen was not mad with Prince William’s decision. The university has some royal connections that delighted Queen Elizabeth II.

“The Queen was delighted that her grandson had enrolled at the elite college where the Scottish King James V studied in the early sixteenth century,” the expert added.

Queen Mother also received a Doctor of Laws degrees in the same university. It was one of the honorary degrees she received in her lifetime.

Unfortunately, Prince William’s stay at St. Andrews University wasn’t smooth sailing. The prince eventually got bored and missed the nightclubs in London. After his first semester, he didn’t want to return to the university and wanted to quit school.

Prince Philip did not like Prince William’s plan to quit school. The Duke of Edinburgh advised him to “knuckle down and not wimp out.”

Good thing Middleton was attending the same school and they were friends. The Duchess of Cambridge saved Prince William from a personal disaster by giving him a brilliant idea about his course.

According to the Amazon Prime documentary “Kate Middleton: Working Class to Windsor,” Middleton advised Prince William to change his course instead of quitting for good. The duke swapped Art History for Geography and earned a second-class honors degree.