When the Duke and Duchess founded their own Instagram account to communicate directly with their public, it was assumed they were beginning a new era as inspirational royal influencers.
Few, however, could have predicted how quickly their unborn child would join them to make his or her mark on the world.
The SussexRoyal Instagram page has posted a message on behalf of “Baby Sussex”, thanking fans for the many charity donations they have made in honour of the future seventh-in-line to the throne.
In a post praising the public for choosing “"to be part of the collective good”, they relayed the success of a week-long charity drive and told 4.6 million followers: “You made this happen. Thank you.”
Remarkably, the post referred to their future child as “Baby Sussex, the nickname used by fans and the press but never before adopted in official palace communications.
The Duke and Duchess had last week named four charities for fans to donate to in lieu of sending gifts for their baby, urging them to help underprivileged children in the UK, Los Angeles and South Africa.
In an update posted on Monday afternoon, in time for their American audience waking up, the couple said: “Not only did many of you lend your support, you took action.”
While the language of the post, including Americanised spellings, led enthusiastic fans to believe it was written by the Duchess herself while on maternity leave, it is understood to have been posted by a member of staff.
"Their royal highnesses wanted you to know the impact of your support - the direct effect your donation, energy, and action made!" it said.
"YOU chose to be part of the collective good, and you have a [sic] made a real difference.
"Whether a $5 donation, £1000 contribution, offering to volunteer, or spreading the word – you’ve played your part.
"And on behalf of The Duke and Duchess (and Baby Sussex), we thank you so much."
It was the latest of a dozen posts shared in the last two weeks, including 63 pictures. Four messages have been based on public engagements undertaken by the Duke, five have included details of the baby charities, and one announced Prince Harry’s television collaboration with Oprah Winfrey.
The Duke and Duchess had asked the public to donate to four children's charities: Lunchbox Fund, Well Child, Baby2Baby and Little Village.
In an update on Monday, the royal account told its followers that Lunchbox can now provide 100,000 additional hot nutritious meals to children in need across South Africa.
Little Village, a clothes, toys and equipment bank for young children in London, has received donations from around the world, “had a surge in volunteer applications, and re-energized their hard working team of 200+ staff and volunteers”.
Well Child, which helps seriously ill children to be cared for at home, can now provide more than 300 additional hours of specialist care by a Well Child nurse thanks to the donations.
Baby2Baby, which helps children and parents in need in the Duchess’s home city of Los Angeles, has received more than 5,000 products including cots, books, backpacks and nappies, along with money.
The Duke and Duchesses’ request followed a viral global baby shower campaign started by fans which raised more than £22,000 after well-wishers donated to animal rescue centre Mayhew, the Campaign for Female Education (Camfed), and WellChild.
The Sussexes' baby is due later this month, with Buckingham Palace announcing last week: "The Duke and Duchess of Sussex are very grateful for the goodwill they have received from people throughout the United Kingdom and around the world as they prepare to welcome their baby.
"Their Royal Highnesses have taken a personal decision to keep the plans around the arrival of their baby private."