Crown Princess Leonor (17) is currently completing her basic training with the Spanish military. In this context, there was now an important date that was also attended by her parents, King Felipe (55) and Queen Letizia (51): the swearing-in ceremony at the military academy in Zaragoza, Spain.

Among other things, the Princess of Asturias took the oath to the flag (Jura de Bandera) in her military uniform and traditionally kissed the Spanish flag after swearing allegiance to her king. She also marched with her fellow cadets in the courtyard of the academy and she presented the rifle. After the Spanish anthem played, King Felipe, who presided over the ceremony, inspected the troops and passed his daughter. Both remained professionally serious.

Princess Leonor, who turns 18 at the end of this month, had been rehearsing for this moment for four hours a day all week, local media reported. Leonor’s training in Zaragoza follows a strict schedule during the week, but the princess can go home on weekends provided there are no maneuvers.

Letizia, who accompanied the king, hardly showed her pride. While the monarch wore his military uniform, she opted for a sleeveless light blue and black polka dot three-quarter length dress with a cinched waist. Leonor’s sister, 16-year-old Infanta Sofia of Spain, was not present at this Saturday’s event as she studies at UWC Atlantic College in the Welsh county of Vale of Glamorgan. The school is often referred to as the “hippie Hogwarts” because of its progressive educational approach and picturesque castle setting.