The Duchess of Cambridge's private secretary is to leave her post in the summer after 10 years service to the royal family, Kensington Palace has confirmed.
Rebecca Deacon has been Kate's right-hand woman since being appointed in 2012, the year after the Cambridges married.
The news comes after reports Ms Deacon is engaged to Adam Priestley and will marry later this month.
Often seen standing discreetly behind her royal boss during engagements, Ms Deacon played an important role during the Duke and Duchess' wedding.
A private secretary's duties include organising official programmes and engagements and ensuring Kate is briefed on who she is going to meet.
Before joining William and Kate's household Ms Deacon worked for Prince Harry's charity Sentebale.
A Kensington Palace spokeswoman said: "After a decade of service to the Duke and Duchess of Cambridge and Prince Harry, Rebecca Deacon will be stepping down as private secretary to the Duchess of Cambridge. She plans to leave the household in the summer.
"Their Royal Highnesses are incredibly grateful for all the hard work and support Rebecca has provided over the past ten years, and wish her well in the next phase of her career."