As hoped, there are new photos of Prince Louis in honor of his fourth birthday tomorrow. 
The Duchess of Cambridge took the pictures.
They were shot earlier this month in Norfolk, near the family’s country home, Anmer Hall. 
More from People’s story:
Bearing a striking resemblance to both brother Prince George, 8, and sister Princess Charlotte, 6, Louis sprints in front of the camera with a smile on his face and playfully holds a cricket ball.
The family of four are regulars at the beaches of North Norfolk, which is a short drive from their Anmer Hall home. Last year, William and Kate shared a sweet family video that showed the children climbing the sand dunes and toasting marshmallows over a fire.
And the fourth photo. 
Some think the Prince looks like his grandfather, Michael Middleton, in the new pictures. Others say he looks like his mother in the new photos, while some believe there is a strong resemblance to his father, as well as his brother, Prince George.
Here is how all three Cambridge children have looked in their 4th birthday photos. 
The young Prince has grown a great deal since he was photographed for his 3rd birthday, which coincided with his first week at Willcocks Nursery School in Kensington.
In the children’s birthday posts, I usually put together a little look back at the past year. Because of the pandemic, there are no Trooping the Colour or Christmas photos, and no other images beyond the family’s 2021 Christmas card. 
Because I cannot do that, here are some of my favorite photos of Prince Louis, beginning with this one taken shortly after his christening. 
At the Chelsea Flower Show in March 2019. 
At Trooping the Colour in June 2019. 
At a July 2019 polo match. 
Joining his big brother and sister when they took part in applauding health care workers in March 2020.
In his second birthday photos. 
On his way to see a special holiday performance at the London Palladium in December 2020. 
Enjoying himself immensely in the 2020 family Christmas card photo. 
And in his mother’s arms in a video shared by the Duke and Duchess on their 10th anniversary. 
Here is a look at how Prince Louis has grown in his birthday pictures.
In the new photos, the Prince is wearing a pair of cotton canvas chino shorts, what looks like a cashmere or wool sweater with intarsia stars, and a checked shirt very similar to the Pepa and Company styles we saw Prince George wear. I have a commitment tonight and will work on identifying the pieces tomorrow.
UPDATE APRIL 23: The grey sweater is by Olivier London, one of the brand’s Star Jumpers. You may remember Prince George wearing a blue Star Jumper by Olivier at a 2015 polo match, seen below. 
Thank you to Charlotte for her comment with the info on the sweater.
The shirt is very much like styles previously worn by Prince George. Below, a closer look at the collar shows the colors. 
The design is similar to the Amaia Kids Ralph style (l) seen on Prince George and the Classic Checkered Shirt by Pepa and Company, a style also worn by Prince George. 
I haven’t been able to find the Prince’s shorts. They look like they are made of cotton canvas, with a front zipper, two front pockets, as well as a front coin pocket on the right side. If looking to get a similar style, here are a few options; on the left, H&M’s Cotton Chino Shorts ($9.99); J. Crew’s Stretch Chino Shorts ($29.50); Target’s Volcom Boys Shorts ($31.50). 
I will have more time to look for the shirt and shorts tonight and will update the post if I learn anything more about the pieces.
This year I think it is more-than-likely we will see Prince Louis on the balcony at Buckingham Palace for Trooping the Colour. Because it is part of the four-day celebration of the Queen’s Platinum Jubilee, it is on a Thursday this year, June the 2nd.
https://donacarmen.com/en/8600–baltic-shorts-fez-.html#/411-size-3_years/684-color-baltic
The Shorts
Hi Jess, and thank you for your comment suggesting the Doña Carmen shorts! They are a great repli-Louis, but they aren’t the shorts worn by Louis. His pair has a double row of topstitching on the zipper, and the Doña Carmen doesn’t. But they’re a fab stand-in! 🙂
It’s so obvious, but I have to say it: He looks so tall for 4! All three Cambridge kids have inherited the long leg genes. And he’s so delightfully happy. So nice to see.
Such delightful pictures. I love how the shirt collar is uneven, the jumper edges a touch ragged, and the shorts well crumpled – a dashing casual look on a very handsome young man!
The Olivier London star jumper is cute without being babyish, the shorts are a most enviable shade of green, and that full, thick fringe most flattering. Definitely a star in the making here! Thanks for the pic gallery.
Louis is actually bowling with the cricket ball (not just ‘sprinting’ as the magazine reported), it’s so nice that he’s fond of one of his great-grandfather’s favourite sports ?
Love the photos of Prince Louis and of course, the clothes he and his siblings wear. Thank you for researching the origin of the outfits and offering less expensive knock offs! Really, their clothing looks just as ordinary as ours does. Gone are the days when royal children were dressed in mink and ermine robes and satin slippers!
So cute, lovely pictures.
Little Louis’ sweater is an old style from Olivier London, I’m guessing it’s a hand-me-down from his brother ❤️ Very sweet pictures of the little birthday boy!
Thank you, Charlotte!