Prince Christian, second in line to the Danish throne, joined dozens of other toddlers Tuesday for his first day at a public nursery school.
The 17-month-old prince arrived at the Dronning Louise Children's House, north of Copenhagen, together with his parents, Crown Prince Frederik and Australian-born Crown Princess Mary.
After being greeted by nursery school staff, the family paused briefly for photographers before entering the building, which is surrounded by a playground.
They live in an annex of the nearby Fredensborg Castle, 35 kilometers (20 miles) north of Copenhagen.
Christian was born on Oct. 15, 2005. His mother is due to give birth to the couple's second child in May, reports AP.
Mary married Frederik two years ago in Copenhagen after meeting him in Sydney during the 2000 Olympics. Frederik is Queen Margrethe's eldest son.
Riyadh will not make contradictory statements, nor will it ask for explanations, as Moscow does in the case of the poisoning of Sergei Skripal