Queen Elizabeth II had a deliberate plan when she sent Prince William to a royal trip years ago.

In 2010, the monarch asked the Duke of Cambridge to open the new Supreme Court in Wellington on her behalf. At the time, New Zealand’s Prime Minister was John Key.

According to royal biographer Robert Hardman in his new book “Queen of the World,” the Queen was planning to do it herself. However, she changed her mind because she wanted to promote the younger generation of the royal family.

“Her decision not to was nothing to do with long-haul travel, but because she thought the time had come to promote the younger generation,” Key told Hardman.

“She could have come to open the Supreme Court because she had come a year later to Australia,” Hardman wrote quoting Key.

He added that it’s not true that Queen Elizabeth couldn’t handle the flight. It’s just that she “really wanted to introduce the young royals to the Commonwealth.”

“She had a very deliberate plan,” Key added.

Last week, Prince William visited New Zealand again on behalf of the monarch. The Duke of Cambridge’s visit was made following the devastating Christchurch mosque massacre that killed 50 people.

On Thursday, Prince William attended Auckland’s Civic Centre to pay respect to Anzac veterans. He also visited the Noor mosque and spoke to the attack survivors. Prince William delivered a warm message during his visit telling them that he stands with them.

In related news, Prince William and Middleton celebrated their eighth wedding anniversary on Monday. However, the infidelity rumors linking Prince William to their friend Rose Hanbury continues.

The Duke of Cambridge was subjected to harsh memes due to the issue. Some compared the second-in-line to the throne to a donkey. Another compared him to a fish and a bald character.

Despite the rumors, Prince William and Middleton are not showing any signs of a strained marriage in their recent outing. The couple was in good spirit when they joined the other members of the royal family on Easter Sunday.

According to Omid Scobie, the Duke and Duchess of Cambridge usually celebrate their wedding anniversary as a family event. Prince William and Middleton were expected to enjoy the new milestone of their marriage with their three kids Prince George, Princess Charlotte and Prince Louis, who just turned 1-year-old last week.

Queen Elizabeth II and Prince William
Prince William and Queen Elizabeth II chat 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