Kate Middleton’s secret weapon in winning Prince William and the royal family has been revealed. 

The Duke and Duchess of Cambridge have been married for eight years already. Biographer Andrew Morton revealed what Middleton has that won the prince and the royal family and it’s something that would surely surprise many.

“It was her family and her home, where William quietly spent time on weekend Army leave, that were ultimately to prove her secret weapon,” Morton wrote in his 2011 book “William and Catherine.”

According to Morton, Prince William was an old-fashioned man who is “attracted to home, hearth and family.” The second in line to the throne saw these things in Middleton.

“The very normality of like with Kate, as well as the steadiness of her family – he eventually began calling Michael Middleton ‘Dad’ – had a profound appeal for a young man who, when all was said and done, was the product of an unhappy marriage within and often distant, and occasionally chilly, family.”

Also, Middleton doesn’t make any effort to steal the spotlight from Prince William. Marcia Moody, author of “Kate: A Biography,” said that she was there for Prince William for 10 years and slowly made her way into the public’s consciousness like a “royal family’s stealth missile.”

Middleton remained unnoticed in Prince William’s life for many years while they were dating. She was with the future king’s side eighth years before they got engaged and was a “low-key public presence” for the most part.

Royal reporter Ashley Pearson also revealed that the Queen is “very fond” of Middleton for the same reason – her family and “middle-class values.” Queen Elizabeth II reportedly liked the fact that she is very close to her family.

In addition, Her Majesty is pleased that Middleton “never tried to garner extra attention for herself.” There is nothing flashy or showy in the duchess.

Prince William and Middleton are now parents to three adorable royal children Prince George, Prince Louis and Princess Charlotte. The family of five was last seen together on Buckingham Palace balcony for Trooping the Colour.