The Duchess of Sussex has dropped two unseen photos of her son Prince Archie to mark his seventh birthday on Thursday.

Meghan Markle posted the photos on Instagram, accompanied by a touching note to her eldest child with Prince Harry.

“Seven years later…happy birthday to our sweet boy,” she wrote.

One of the photos shows a newborn Archie sleeping under a cream-coloured blanket on his father’s chest. The other shows the little boy walking on the beach near the Sussexes’ family home in California with his four-year-old sister Princess Lilibet.

Archie and his sister Lilibet. Photo: Instagram/Meghan

Harry and Meghan have lived at Montecito in California since 2020, after quitting as senior royals and leaving Britain.

Archie was born in London’s Portland Hospital while his sister was born at the Santa Barbara Cottage Hospital in California.

The family’s luxury Montecito neighbourhood is also home to a host of other celebrities, including Oprah Winfrey, Ellen DeGeneres, Rob Lowe, Ariana Grande and Jeff Bridges. Winfrey alone reportedly owns three Montecito ranches collectively worth about $US90 million ($A124 million) and covering nearly 30 connected hectares.

Despite the luxury surroundings, Meghan has previously spoken of raising her children with “normalcy”.

“Once you know us, I think you want us to have the same normalcy as parents and for our children as they do,” she told People magazine.

That includes day dates with her son.

“Archie and I like to go and have lunch, share a burger and a Caesar salad, and have an ice-cream sundae with two cherries on top,” she said.

Harry and Meghan have largely given their children a private upbringing, although the duchess has revealed more of them in recent social media posts.

About a month ago, Archie featured in an Instagram video skiing with his father, while both children appeared in a post promoting Meghan’s Netflix lifestyle show a few weeks before that.

She also shared a sweet photo for Archie’s sixth birthday last year – – an atmospheric shot of him wearing pyjamas and staring out into the sunset.

Meghan revealed the little boy had a sixth birthday party, although she gave no more details. Lilibet, meanwhile, was treated to a trip to Disneyland for her fourth birthday in June.

Most recently, Meghan revealed that her children – like millions the world over – are fans of Australian cartoon Bluey.

“Our kids love Bluey,” she during an appearance on the Get Down with Sean and Marley podcast that was released earlier this week.

The Australian YouTubers showered Meghan with Australian-themed gifts, including NRL jumpers for the kids, cuddly toys, chicken salt, Tooheys beers and swim trunks for Harry.

“That’s going to be for my husband. I just have a feeling,” Meghan said as Sean Skeels and Marley Whatarau presented her with the budgie smugglers.

“For the love of my life. We might renew our vows with him wearing these.”