Prince William, Kate Middleton, Meghan Markle and Prince Harry
Prince William and Kate Middleton caused tension in their relationship with Meghan Markle and Prince Harry. Pictured [L-R]: The Duke of Cambridge, Duke of Sussex, Duchess of Sussex and Duchess of Cambridge arrive at Westminster Abbey to attend a service to mark the centenary of the Armistice on Nov. 11, 2018 in central London. Paul Grover/AFP/Getty Images

Last year marked the beginning of ongoing feud rumors between Kate Middleton and Meghan Markle. However, by 2019, the tension reportedly began to extend to their husbands Prince William and Prince Harry.

While reports continue to speculate why the couples have become foes rather than supporters of one another, a relationship expert seems to believe competition has played a big role in the royal feud.

Kate Mansfield told the Express UK, Kate and William may be under the impression that they are in an unspoken competition with Meghan and Harry.

“I imagine that a big part of the alleged tension between Meghan and Kate is an edge of competition between the royal brothers and their wives and that Kate and William might feel a little less glamorous than Harry and Meghan,” she revealed.

Prior to her comment, in the TLC documentary “Kate v Meghan: Princesses At War,” editor of Majesty Magazine Ingrid Seward suggested the Duke and Duchess of Cambridge hold some resentment toward the former “Suits” actress for affecting their relationship with Prince Harry.

“He was very much a part of their family. Then suddenly he meets Meghan and he falls in love and he’s off. So he’s sort of suddenly out of their lives and there may have been some resentment,” she explained.

Meanwhile, royal biographer Katie Nicholl claimed William and Harry’s relationship reportedly began to fall apart when the Duke of Cambridge revealed he thought his brother’s romance with Meghan was moving too fast.

“Harry is hugely protective of Meghan, he saw that as criticism, he interpreted that as his brother not really being behind this marriage, this union, and I don’t think things have been quite right ever since,” she stated.

Kensington Place has not acknowledged comments suggesting there is a feud going on between members of the royal family.