Kate Middleton is the royal family’s “stealth missile.”

The Duke and Duchess of Cambridge have built a strong relationship before they finally decided to tie the knot in 2011. Unlike her sister-in-law, Meghan Markle, Middleton didn’t immediately capture the public’s interest, according to Marcia Moody in her book “Kate: A Biography.”

“For over ten years she has been the person closest to the man who will one day be king but she only slowly slipped into the public’s consciousness, like the royal family’s stealth missile,” Moody wrote.

“Kate was able to enter the prince’s life unnoticed at first, while they worked out how they felt about each other – a luxury unheard of for previous generations of royals,” she continued.

Prince William and Middleton’s relationship lasted for 10 years before they finally exchanged “I dos” and it gave the duchess a long time to adjust to the demands of a royal life. The royal biographer pointed out that Middleton was there for the second-in-line to the throne and remained a low-key public figure until their engagement.

“It was only when their engagement was announced that the spotlight was shone square on her and she became one of the most famous women in the world,” Moody wrote before adding that by that time, Middleton had already become a “valuable asset to the royal family.”

The author also pointed out how the Duke and Duchess of Cambridge symbolized the new royal generation that’s primarily about mending and making changes. For instance, Prince William stepped in when Middleton was harassed by the media. He issued a statement to stop harassing his girlfriend. Prince Harry did the same when the media was after Markle following their publicized royal romance.

There’s no question about Middleton and Prince William being there for each other. For one thing, the duchess saved the future king many times. One time from a flirty partygoer and another from a possible personal disaster when Prince William wanted to quit school.

However, others might disagree with Moody’s claim that Middleton is an asset to the royal family. Just recently, netizens complained that the Duchess of Cambridge didn’t level up eight years after joining the royal family. One Twitter user said that she seemed stuck at year one and another called Prince William’s wife “duchess do little.”

Kate Middleton
Kate Middleton is branded as the royal family’s “stealth missile” for this reason. Pictured: Middleton engages in a walkabout in Ballymena town centre on Feb. 28, 2019 in Ballymena, Northern Ireland. Getty Images/Charles McQuillan