Danish Crown Prince Frederik (L) and Crown Princess Mary (R) are pictured with their twins Prince Vincent (Center R) and Princess Josephine (Center L) in front of Amalienborg Castle in Copenhagen on the sibling's first day of school on August 15, 2017. 
The Prince and Princess will be attending Tranegaard School in Hellerup north of Copenhagen as their older siblings Prince Christian and Princess Isabella.  / AFP PHOTO / Scanpix Denmark / Liselotte Sabroe / Denmark OUT        (Photo credit should read LISELOTTE SABROE/AFP via Getty Images)