For most women, turning 40 signals the onset of middle age and daunting fears about growing old.

But for the Duchess of Sussex, who once described birthdays as a chance to “make resolutions just for yourself”, it prompted a slick promotional video in a bid to launch her latest charitable initiative “to help women regain confidence and rebuild their economic strength”.

On turning 40 on Wednesday, Meghan teamed up with Bridesmaids actress Melissa McCarthy to launch her new “40×40” project to encourage the rich and famous to donate 40 minutes of their time mentoring those who have “shouldered the brunt” of the Covid crisis. 

The pair recorded a short film to kick-start the campaign in which a hat-wearing and white-glove wearing McCarthy put on a show of drinking tea from a cup and saucer like royalty and Prince Harry was briefly spotted juggling in the background. 

Filmed at the couple’s £11million Montecito mansion with Meghan’s beagle Guy sleeping in the background, the Duchess, looking serene in a cream outfit and brown high heels, chats to McCarthy on a propped up laptop, with multiple copies of her children’s book The Bench in the foreground. 

To a soundtrack of jaunty piano music, the celebrity friends joke about the Duchess’s fondness for having pensive photographs taken under trees and getting matching tattoos as family photographs of their son Archie, two, and Harry kissing a baby can be seen in the background. 

The couple have yet to release an image of their daughter Lilibet, who was born in June. At the end, Meghan blows out a single candle on a birthday cake topped with buttercream icing and mixed berries that appears to have been made by Santa Barbara bakery Posies & Sugar. 

Alongside the two-minute footage, which was posted on the Sussexes’ Archewell website, the royal mother-of-two penned a personal message in which she reflected on her 40th birthday, described time as “among our greatest and most essential gifts.”

“Time with our loved ones, time doing the things we love, time spent learning, laughing, growing, and the sacred time we have on this earth,” she added.

“Amongst the most valuable gifts of time is also time spent in service to others knowing that it can contribute to incredible change. 

“With my 40th lap around the sun in mind, it made me wonder: what would happen if we all committed 40 minutes to helping someone else or to mentoring someone in need? And then what would happen if we asked our friends to do the same?”

Explaining how the pandemic had caused “tens of millions of women around the world” to leave the workforce, while “shouldering the brunt of the crisis when it comes to unpaid labour, including schooling and caring for family members,” she claimed fewer women than men would return to their careers. 

“For my birthday, I have asked 40 friends, activists, athletes, artists, and world leaders to help kickoff a global effort by contributing 40 MINUTES OF MENTORSHIP to support women re-entering the workforce. With this time, I hope they each help someone advance a professional life on her own terms, and, I hope that they inspire countless others to give 40 minutes of their time as well.”

The likes of singer Adele, fashion designer Stella McCartney and Sophie Grégoire Trudeau, wife of Canadian Prime Minister Justin Trudeau, have also signed up to the campaign.

The announcement came after the Queen, Prince Charles and the Duke and Duchess of Cambridge all shared well-wishes to Meghan.

Buckingham Palace was the first to post on Instagram and Twitter, sharing three photos of Meghan along with the message: ‘Wishing the Duchess of Sussex a very happy birthday today!’

🎈 Wishing The Duchess of Sussex a very Happy Birthday today! pic.twitter.com/xvrRH4sEwX

— The Royal Family (@RoyalFamily) August 4, 2021

One of the photos shows the Queen, 95, and Meghan smiling on their first and only joint engagement in June 2018. 

Within minutes, Prince William and Kate Middleton and Prince Charles and the Duchess of Cornwall added their own birthday messages.

In describing the new 40×40 project as a “global wave of service”, Meghan appears to have taken inspiration from the Nelson Mandela Foundation, which in 2009 invited people to “start with 67 minutes” of helping others in recognition of the 67 years the former president of South Africa spent fighting for social justice.

Mandela Day was described as a “global call to action that celebrates the idea that each individual has the power to transform the world, the ability to make an impact.”

Reports that Meghan has enlisted top party planner, Colin Cowie, to organise a low-key celebration for 65 friends have been denied amid the worsening coronavirus situation in California.

US President Barack Obama, who turned 60 on Wednesday, has been criticised for holding a party for 500 at his Martha’s Vineyard home this weekend. Harry and Meghan are not expected to attend.

Last year, Meghan enjoyed a quiet birthday at home amid the pandemic, five months after she and Harry sensationally quit the Royal Family and moved to the US.

In a post on her now defunct blog, The Tig, in 2016, Meghan wrote: “My mom has always said that birthdays are your own personal New Year.

"Your own chance to make resolutions just for yourself and what you prognosticate for your year ahead."

The Duke and Duchess of Sussex mulled moving to New Zealand

For the Duchess’s 36th birthday a year later, the prince took her away to Botswana where they carried out conservation work with the charity Elephants Without Borders.

She marked her 37th – her first birthday as an official member of the Royal Family – at the wedding of Harry’s friend Charlie van Straubenzee and Daisy Jenks in Surrey.

On her 38th, which was Meghan’s first as a mother, having given birth to son Archie in May 2019, the couple held a private celebration at their Frogmore Cottage home in Windsor before flying to Ibiza.