“Things did get very bad between the brothers and they didn’t see each other privately for a number of months”
Dubbed the “Fab Four” when they all appeared together onstage for the Royal Foundation’s first Q&A last year, the Royals appeared to have healed the rumoured rift.
But, just 18 months on, it is understood that Prince Harry, 34, and Meghan Markle, 37, will go their own way.
The couples will use the breakaway to devote more time to their individual charities separately.
Royal sources were quick to add the split does not mean the two couples will not work on upcoming projects in the future.
A source did tell The Sun, however, that the two princes had a rocky relationship during their time working together and that it has improved since they began working independently.
They added: “Things did get very bad between the brothers and they didn’t see each other privately for a number of months after the royal wedding.
“Certainly the animosity over status, money and Meghan meant that the split in their joint households had to be brought forward much more quickly than anticipated, so perhaps it was inevitable that their joint charity has to be split too.
“Meghan and Harry want to do things differently to William and Kate. William is the future king and so is sometimes restricted in what he can do.
“The Sussexes want the flexibility of more commercial decisions. But the brothers’ relationship has vastly improved since their working lives have separated.”
It comes after Meghan and Harry didn’t see Kate, 37, and Wills, 36, for six months after they tied the knot.
The reported fall-out is understood to be because of an ongoing feud between Meghan and Kate.
Kensington Palace has always strongly denied there is, or ever has been, a rift between the pair.