Meghan Markle shared a rare and heartfelt tribute to her son, Prince Archie, in honor of his 6th birthday.

“Our son. Our sun,” Meghan, 43, began in the caption of a photo showing Archie looking out at a sunset over the ocean on Tuesday, May 6.

“Happy 6th birthday to Archie! Thank you for all of the love, prayers and warm wishes for our sweet boy. He’s 6! Where did the time go?” she continued.

The Duchess of Sussex also revealed that she and husband Prince Harry threw a celebration for their first-born child the weekend prior, adding, “And for all of you who came to celebrate with us at his party last weekend, thank you for making his birthday so incredibly special.”

The post marks the first time Meghan has shared a birthday tribute to one of her children, as she joined Instagram under her own personal account on January 1. Prior to that, the “Confessions of a Female Founder” podcaster had only used the platform for her former brand, American Riviera Orchard.

In addition to Archie, Meghan and Harry, 40, share daughter Lilibet, 3.

Once again, the duchess maintained Archie’s privacy by not showing his face, as he was turned away from the camera in the photo. But the picture showed how much he’s grown, standing well above a railing in a striped shirt and pants set.

Archie was born in London, England, when Harry and Meghan were still senior working members of the British royal family. He made his debut to the world on May 8, 2019, when the couple showed off their newborn for selected members of the press at Windsor Castle. They decided to forgo the royal tradition of posing outside of the hospital with their infant.

While Archie was too young to know it, he had several major milestones as a royal. He was christened at Windsor Castle on July 6, 2019, with King Charles III, wife Queen Camilla and Harry’s brother and sister-in-law, Prince William and Princess Kate Middleton, in attendance. Meghan’s mother, Doria Ragland, represented her side of the family.

Archie also accompanied his parents on a royal visit to South Africa in September 2019. He looked adorable when the trio met with Archbishop Desmond Tutu, as he smiled and squirmed in his mom’s arms.

Harry and Meghan announced their decision to step away from royal duties in January 2020. While they hoped for a half-in, half-out status that allowed them to seek financial independence abroad while still making a handful of royal appearances, the late Queen Elizabeth II nixed the idea.

Instead, the couple came to an agreement where they were allowed to keep their “Royal Highness” status in private while promising not to use it publicly, since they were no longer working royals. Harry and Meghan eventually settled in Montecito, California, and went on to sign megabucks deals with Netflix and Spotify.

The With Love, Meghan star raised eyebrows recently when it was revealed that she used her HRH title on a card to pal Jamie Kern Lima.

Jamie, 47, showed off on her podcast how Meghan sent her “homemade strawberry sauce,” while the former Suits star signed the card, “With the Compliments of HRH The Duchess of Sussex.”

The card showed Meghan’s royal cypher with an embossed “M” underneath a crown, which is the same one she used in royal life prior to leaving the family.

Royal commentator Jennie Bond exclusively told In Touch that the move was “rather crass and pompous of Meghan.”

“You really shouldn’t try to bake your cake and eat it! She turned her back on royal life … Why does she want to cling on to any vestige of a life she so clearly despised?” Jennie explained. “I thought America was all about equality … so why try to be superior?”