The Duke and Duchess of Sussex are to set up their own charitable foundation, splitting from the Royal Foundation and the Duke and Duchess of Cambridge.

The breakaway comes as Harry and Meghan plan to pursue their charitable interests separately, and is seen as the final step in the division of the two couples’ public duties. The announcement of the split followed a meeting between William and Harry and trustees of the Royal Foundation to finalise the arrangements.

The Cambridges will remain with the original charity, which will be renamed the Royal Foundation of the Duke and Duchess of Cambridge. Royal aides had previously said the foursome were to remain joint patrons of the foundation.

In the spring the Sussexes announced their decision to set up their own household and to move away from Kensington Palace and the Cambridges. Their offices are now at Buckingham Palace and their royal residence is at Frogmore Cottage, Windsor. They have their own public relations chief and a separate Instagram account, SussexRoyal.

The Royal Foundation was originally set up in 2009 by William and Harry, with Kate joining when she became the Duchess of Cambridge in 2011 and Meghan on becoming the Duchess of Sussex in May 2018.

Despite rumours of a rift between the two couples, first between Kate and Meghan and then between the two royal brothers, aides maintain that the priorities and agendas of the two couples are different, given that William and Kate are the future Prince and Princess of Wales and that ultimately William will become king. This means the Cambridges are more constitutionally constrained than the Sussexes.

Kensington Palace said: “These changes are designed to best complement the work and responsibilities of Their Royal Highnesses as they prepare for their future roles, and to better align their charitable activity with their new households.”

Facebook Twitter Pinterest The nickname the Fab Four stemmed from the couples’ appearance at the first and only Royal Foundation forum in 2018. Photograph: Chris Jackson/AFP/Getty Images

Both couples – who have together been nicknamed the Fab Four – will continue to work together in future, including on the Heads Together mental health campaign.

The nickname arose after the four took to the stage together at the first – and so far only – Royal Foundation forum in London in February 2018.

During the Q&A they were asked whether there were disagreements, with William replying: “Oh yes.” Harry said there were “healthy disagreements”, and said he could not remember if they had all been resolved as they “come so thick and fast”. Meghan said: “Thank goodness [there are] such differing personalities and everyone’s very communicative because that’s how you can really see bigger change.”