Princess Mary of Denmark's twins steal the show on first day of school

The six-year-old twins joked around with their parents Prince Frederik and Princess Mary

With excited smiles and backpacks full of essentials, Prince Vincent and Princess Josephine set off for their first day of school on Tuesday. The six-year-old twins, who are the youngest children of Princess Mary and her husband Prince Frederik, completely stole the show as they posed for photos outside their home, Amalienborg Palace, in Copenhagen.

Vincent was smartly dressed in a blue shirt and green shorts, while his younger sister Josephine looked adorable in a blue summer dress with a red flower in her hair. The princess was her usual lively self, joking around with her dad as he spun and twirled her around in the palace forecourt.

Princess Josephine, six, was her usual lively self

GALLERY: Josephine and Vincent's most precious moments

It was a proud moment for Frederik and Mary as their youngest children started Grade 0 at Tranegård School in the Hellerup district of the capital city. Their older children Prince Christian, 11, and Princess Isabella, ten, also attend the same school; they were the first Danish royal children to attend a public school.

The family of six have been enjoying their summer in Denmark. Frederik and Mary enjoyed a sailing trip with their brood around the country, stopping off at local sights. The palace shared photos of their holiday on Instagram, showing the young princes and princesses having a whale of a time.

The twins have been enrolled at Tranegård School

Earlier this summer, there was extra excitement among the children as the royals welcomed a new member to their family – a pet dog called Grace. Posting a photo on Instagram in July, the palace announced: "Yesterday the Crown Prince family welcomed their new dog Grace at Gråsten Castle. Grace is a border collie and is from the same family as the family's former dog Ziggy." The royal family's pet dog Ziggy sadly died in April. He had been a part of the family for 12 years and was a wedding gift to Mary and Frederik.