“William and Catherine may have unconsciously raised their game” in order to compete with Markle.

Prince William and Kate Middleton were able to maintain the spotlight for quite some time, with the couple having all eyes on them from the time they started dating in 2002 until after their marriage and the welcoming of their children. But when Meghan Markle came into Prince Harry’s life, the attention suddenly shifted from William and Middleton, and according to a royal biographer, the couple wasn’t happy about it.

Royal expert Robert Jobson spoke of the events that led up to the former Fab Four’s famous royal rift in his new book, Catherine, the Princess of Wales: A Biography of the Future Queen, and explained that the tabloid focus on Markle may have led to discontent amongst the Prince and Princess of Wales.

“At first, public reaction to Meghan was overwhelmingly positive, with ‘the new kids on the block’ hogging most of the headlines—to the point that William and Catherine may have unconsciously raised their game. There were whispers of pettiness, even jealousy,” he wrote. The drama was just the beginning and paved the way for the royal four’s greater issues. “Cracks between the two couples continued to widen—with the help of petty slights, whether imagined or otherwise,” Jobson added.

Jobson recalled an incident that highlighted Middleton’s alleged distaste of Markle. “There was the time Meghan asked to borrow some lip gloss, and Harry felt Catherine had handed hers over reluctantly,” he claimed. “According to him, Catherine ‘grimaced’ after Meghan had squeezed some onto a finger and applied it to her lips.”

And where Middleton and Markle’s trouble began, Harry and William’s relationship with each other began to also falter. “Inevitably, details leaked of the royal brothers’ troubled relationship, and the fact that Catherine and Meghan had also fallen out,” the expert added.

Currently, Harry, William, Middleton and Markle continue to remain estranged. Harry feels guilt over being unable to reconcile with Middleton, while Markle feels like Middleton should be the one to apologize to her first. The brothers are also still on the outs with each other.

“He really misses that warm, uncomplicated relationship, and he is torn between loyalty to his wife and regret about the loss of the woman he was so close to,” royal author Tom Quinn told The Mirror. “Losing Kate was Harry’s second great loss after losing his mother.”