Prince William has a very special relationship with one unlikely royal family member

The royal family has had a difficult start to the year, with both King Charles and the Princess of Wales confirming the news that they have been diagnosed with undisclosed forms of cancer.

Both King Charles and the Princess of Wales made the news of their respective conditions public "in the hope it may assist public understanding for all those around the world who are affected by cancer", telling them "you are not alone".

“It has been an incredibly tough couple of months for our entire family," the Princess of Wales explained in a video message, asking for time, space and privacy.

While both senior royals have been forced to take a temporary step back from duty to focus on their respective recoveries - in what experts are calling the "biggest [royal] crisis" in recent years, Prince William is having to step up as the heir to the throne.

"The weight of the world is on [Prince William's] shoulders," royal expert Robert Jobson explained to HELLO! earlier this month. And as the pressure mounts on the future King, particularly at a time when his wife and father are unwell, his support network is said to be getting tighter.

One relationship that is said to be very special to the Prince of Wales is that with his cousin Peter Phillips, who experts explain is a "sounding board" for the heir to the throne.

"Peter will be a great support to [William] – both as a cousin and as someone who has been there all his life and understands the institution," explained HELLO!'s Royal Editor, Emily Nash. "He has a pragmatic, common sense approach to things and can be a trusted sounding board for the future King."

She continued: "Like the rest of the family, I'm sure Peter is lending his support to William and Kate as they face her cancer treatment."

We will continue to update this story.