Spain's Princess Leonor And Infanta Sofia on the First Day of School in Madrid, Spain on September 11, 2018

Spain's King Felipe VI, Queen Letizia, Princess Leonor (R) and Infanta Sofia (L) arrive at the 'Santa Maria de los Rosales' school on the first day of school on September 11, 2018, in Madrid, Spain.

Spain's Infanta Sofia, right, walked alongside her mother Queen Letizia (left) into Santa Maria de los Rosales school in Madrid

Spain's Infanta Sofia left, and Princess Leonor, right, appeared pleased to be returning to school

Spain's Infanta Sofia, 11, pictured, looked back over her shoulder as she made her way up the steps with her mother, Queen Letizia, who wore a chic grey linen jacket for the casual outing

Spain's Queen Letizia and King Felipe who waved to fellow parents and a handful of photographers who captured their arrival

Spain's King Felipe VI, 50, blended in with the other smartly-dressed fathers in a navy check suit and white shirt, pictured, as he accompanied elder daughter Princess Leonor, 12, into the school

Spain's Queen Letizia and King Felipe VI smiled as he drove their daughters to school himself on Tuesday morning, September 11, 2018

Spain's Queen Letizia remained low-key as she followed her daughter Infanta Sofia, right, inside the school.

Spain's Queen Letizia and Prince Felipe VI appeared in excellent spirits as they drove their daughters to school themselves

Spain's Queen Letizia and King Felipe VI looked perfectly relaxed as they greeted a teacher at the entrance, while other parents, pictured, appeared nonplussed about the VIP drop-off

King Felipe and Queen Letizia of Spain looked every inch the proud parents as they dropped their daughters off for the first day back at school in Madrid today. Pictured, the royal couple leave the school after making sure Princess Leonor and Infanta Sofia were settled

The Spanish King Felipe VI and Queen Letizia appeared deep in conversation as they left the school after dropping off their daughters on Tuesday morning, September 11, 2018. The Royal couple have been married for 14 years

King Felipe and Queen Letizia of Spain arrive at the 'Santa Maria de los Rosales' school on the first day of school of Princess Leonor (R) and Infanta Sofia (3R) on September 11, 2018, in Madrid, Spain.

Queen Letizia of Spain (L) and Infanta Sofia of Spain (R) arrive at the 'Santa Maria de los Rosales' school on the first day of school 2018 in Madrid, Spain

Queen Letizia of Spain, who wore a chic grey linen jacket for the casual outing, who looked every inch the proud parents as they dropped their daughters off for the first day back at school

King Felipe and Queen Letizia of Spain arrive at the 'Santa Maria de los Rosales' school on the first day of school 2018 of Princess Leonor (R) and Infanta Sofia (3R) in Madrid, Spain.

Queen Letizia of Spain arrives at the 'Santa Maria de los Rosales' school on the first day of school of Princess Leonor (3R) and Infanta Sofia (L) on September 11, 2018, in Madrid, Spain.

Spain's King Felipe VI dressed in a navy check suit and white shirt. Meanwhile, the ever-stylish Queen Letizia looked chic in a pair of white jeans and mushroom-colored linen jacket for the casual family outing. Pictured, as they leave the school after dropping off their daughters on their first day of school in Madrid

Spanish Queen Letizia looked chic in a pair of white jeans and mushroom-colored linen jacket as she drops off their daughters on the first day of school.

Queen Letizia of Spain leaves the 'Santa Maria de los Rosales' school after dropped off their daughters on their first day of school 2018 in Madrid, Spain.

Spain's Queen Letizia followed daughter Infanta Sofia inside the entrance of Santa Maria de los Rosales while King Felipe (seen from behind) walked alongside their elder daughter Princess Leonor (not seen behind, right)

King Felipe and Queen Letizia of Spain looked every inch the proud parents as they dropped their daughters off for the first day back at Santa Maria de los Rosales school in Madrid