With rosy cheeks and big brown eyes, this cheeky chappy has clearly inherited a thing or two from his mother.

And if that smile is anything to go by, a passion for the great outdoors can certainly be counted among these.

Little Prince Louis looks gleeful as he crawls, covered in moss, around the garden in three photographs released by Kensington Palace to mark his first birthday today.

The Duchess of Cambridge, a keen amateur photographer, took the glorious portraits at the family's Norfolk home, Anmer Hall, earlier this month. And how time has flown!

The last time we saw Louis – who bears a striking resemblance to his mother at his age –was on the Cambridge family's Christmas card when he was just a babe in arms.

Now Louis is crawling – and very proud of himself, too, by the looks of it.

The fifth in line to the throne is beginning to look more and more like older brother George, with his sweep of blond hair no doubt smoothed with the same styling balm that Kate, 37, uses on her eldest son.

And it's not just the coiffure he's adopted – under his red wool jumper, Louis appears to be wearing one of George's romper suits, identifiable by its distinctive Peter Pan collar with blue piping.

The third in line to the throne has worn several over the years, but this looks most like the £79 ($NZD153) romper by Rachel Riley, which he wore as a youngster on a family trip to New Zealand.

In another photo, Louis wears an adorable blue cashmere mix jumper with a puppy motif from upmarket store Trotters, which is currently on sale reduced from £44 ($NZD87) to £35 ($NZD68).

Although eyebrows were raised when the duchess first started using her own snaps in place of official palace photographs, there's no doubt these candid portraits come to life with a mother's touch – showing Louis in a natural light, happy at play.

The Duke and Duchess of Cambridge are delighted to share three new photographs of Prince Louis ahead of his first birthday tomorrow 🎈

The photographs were taken earlier this month by The Duchess at their home in Norfolk. pic.twitter.com/VOJ7rhKthz

— Kensington Palace (@KensingtonRoyal) April 22, 2019