Posting a snap of Archie's feet to their official Sussex Royal Instagram page, the caption read, 'Paying tribute to all mothers today - past, present, mothers-to-be, and those lost but forever remembered. We honor and celebrate each and every one of you.
'Today is Mother’s Day in the United States, Canada, Australia, New Zealand, South Africa, Kenya, Japan, and several countries across Europe. This is the first Mother’s Day for The Duchess of Sussex. sic
It comes after The Duke and Duchess of Sussex revealed their baby boy's name last week, just hours after he'd been introduced to The Queen and Prince Phillip.
Now that baby Archie is one week old, reports out today suggest Prince William and Kate Middleton will get to meet their nephew for the first time tomorrow (Tuesday 14th May).
Royal expert Omid Scobie told Good Morning America, "Archie's first week at home with mum and dad was quiet, they wanted that personal space with their newborn.
"This week it's all about the visitors with the Duke and Duchess of Cambridge visiting tomorrow and the Prince of Wales visiting later this week."
Check out Prince Harry and Meghan Markle's relationship timeline:
Prince Harry and Meghan Markle met in London in July 2016.
Meghan Markle and Prince Harry share adorable new photo of baby Archie
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In late September 2017, it was reported that Meghan had met the Queen, prompting speculation that the relationship was getting serious.
Prince Harry and Meghan Markle met in London in July 2016.
They were introduced by mutual friend Markus Anderson, who is the director of Soho House.
In October 2016, the Express became the first newspaper to publish news that Prince Harry had a new girlfriend.
On November 8th 2016, Kensington Palace released an unprecedented statement which referring to Markle as Harry's girlfriend for the first time.
In the statement, Prince Harry condemned the 'wave of abuse and harrassment' faced by Markle, saying that he was 'worried about Ms. Markle's safety and is deeply disappointed that he has not been able to protect her.'
'It is not right that a few months into a relationship with him that Ms. Markle should be subjected to such a storm,' the statement continued.
The couple were papped together for the first time in December 2016, shopping for a Christmas tree in London at the Pines and Needles store.
Later that week, they were seen on London's West End, catching a performance of The Curious Incident of the Dog in the Night-Time.
In February, Prince Harry wore a his 'n' hers bracelet on the cover of Town & Country magazine, just weeks after Markle was pictured wearing the same one on Instagram.
In March 2017, Meghan joined Prince Harry in the Caribbean for the wedding of his friend's Tom 'Skippy' Inskip and Lara Hughes-Young.
It was the first time that Markle accompanied Harry to a wedding, marking another milestone occasion for the couple.
The first public event attended by the couple was the polo at Coworth Park in May 2017.
Later in May, Markle attended the party portion of Pippa Middleton's wedding to James Middelton.
Prince Harry was seen driving her to the event after the church ceremony.
The couple were photographed together the following day at the wheelchair tennis.
The couple 'broke with royal protocol' by holding hands and appearing affectionate while at the Invictus Games.
In an interview with Vanity Fair, Meghan referred to Harry as her boyfriend numerous times, saying: 'We're a couple. We're in love. I'm sure there will be a time when we will have to come forward and present ourselves and have stories to tell, but I hope what people understand is that this is our time.'
In early November 2017, it was reported that Meghan Markle was leaving Suits after seven series.
Much was made of Markle's choice of outfit: ripped jeans and a white blouse called 'The Husband'.
Although Prince Harry was sat next to First Lady Melania Trump at the event, rather than his girlfriend, she was only seated a few rows behind him.
The couple made their first official public appearance in September, when Markle attended the opening of Prince Harry's Invictus Games.
In mid-November 2017, bookies suspending betting on an impending royal engagement, as speculation grew that an announcement was about to be made.
On November 27th 2017, Prince Charles announced the engagement of his younger son Prince Harry and Meghan Markle after 15 months of dating.
The couple later appeared at a photocall, with Markle wearing a white dress coat by Canadian brand Line The Label. The website has subsequently crashed.
The engagement ring, by Cleave and Company, was reportedly designed by Prince Harry himself, using two stones that belonged to Princess Diana.
When asked by waiting photographers if the proposal was romantic, Harry joked 'of course!'
The couple indulged in some PDA at the closing ceremony.
Meghan wore a maroon midi dress with a pleated chiffon skirt by one of her favourite Canadian brands Aritzia.
She teamed it with a matching burgundy biker jacket by Mackage.
Prince Harry reportedly spent time with Meghan's mother Doria while at the Games too.
Prince Harry was photographed kissing Meghan.
In late September 2017, it was reported that Meghan had met the Queen, prompting speculation that the relationship was getting serious.
Prince Harry and Meghan Markle met in London in July 2016.
They were introduced by mutual friend Markus Anderson, who is the director of Soho House.
In October 2016, the Express became the first newspaper to publish news that Prince Harry had a new girlfriend.
On November 8th 2016, Kensington Palace released an unprecedented statement which referring to Markle as Harry's girlfriend for the first time.
In the statement, Prince Harry condemned the 'wave of abuse and harrassment' faced by Markle, saying that he was 'worried about Ms. Markle's safety and is deeply disappointed that he has not been able to protect her.'
'It is not right that a few months into a relationship with him that Ms. Markle should be subjected to such a storm,' the statement continued.
The couple were papped together for the first time in December 2016, shopping for a Christmas tree in London at the Pines and Needles store.
Later that week, they were seen on London's West End, catching a performance of The Curious Incident of the Dog in the Night-Time.
In February, Prince Harry wore a his 'n' hers bracelet on the cover of Town & Country magazine, just weeks after Markle was pictured wearing the same one on Instagram.
In March 2017, Meghan joined Prince Harry in the Caribbean for the wedding of his friend's Tom 'Skippy' Inskip and Lara Hughes-Young.
It was the first time that Markle accompanied Harry to a wedding, marking another milestone occasion for the couple.
The first public event attended by the couple was the polo at Coworth Park in May 2017.
Later in May, Markle attended the party portion of Pippa Middleton's wedding to James Middelton.
Prince Harry was seen driving her to the event after the church ceremony.
The couple were photographed together the following day at the wheelchair tennis.
The couple 'broke with royal protocol' by holding hands and appearing affectionate while at the Invictus Games.
In an interview with Vanity Fair, Meghan referred to Harry as her boyfriend numerous times, saying: 'We're a couple. We're in love. I'm sure there will be a time when we will have to come forward and present ourselves and have stories to tell, but I hope what people understand is that this is our time.'
In early November 2017, it was reported that Meghan Markle was leaving Suits after seven series.
Much was made of Markle's choice of outfit: ripped jeans and a white blouse called 'The Husband'.
Although Prince Harry was sat next to First Lady Melania Trump at the event, rather than his girlfriend, she was only seated a few rows behind him.
The couple made their first official public appearance in September, when Markle attended the opening of Prince Harry's Invictus Games.
In mid-November 2017, bookies suspending betting on an impending royal engagement, as speculation grew that an announcement was about to be made.
On November 27th 2017, Prince Charles announced the engagement of his younger son Prince Harry and Meghan Markle after 15 months of dating.
The couple later appeared at a photocall, with Markle wearing a white dress coat by Canadian brand Line The Label. The website has subsequently crashed.
The engagement ring, by Cleave and Company, was reportedly designed by Prince Harry himself, using two stones that belonged to Princess Diana.
When asked by waiting photographers if the proposal was romantic, Harry joked 'of course!'
The couple indulged in some PDA at the closing ceremony.
Meghan wore a maroon midi dress with a pleated chiffon skirt by one of her favourite Canadian brands Aritzia.
She teamed it with a matching burgundy biker jacket by Mackage.
Prince Harry reportedly spent time with Meghan's mother Doria while at the Games too.
Prince Harry was photographed kissing Meghan.
In late September 2017, it was reported that Meghan had met the Queen, prompting speculation that the relationship was getting serious.
Former Suits actress Meghan gave birth to her son at 5.26am on Monday 6th May, with the couple's son weighing 7lbs. 3oz.
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